Contents

  1. Precautions···········································2
  2. Conveyance of the Grinding Machine·······················2
  3. Specifications of the Grinding Machine······················3
  4. Installation of the Grinding Machine························4
  5. Mechanical Structure of the Grinding Machine················6
  6. Operation of the Grinding Machine·························6
  7. Electrical System of the Grinding Machine··················12
  8. Schematic Diagram of the Hydraulic System··················15
  9. Wearing Parts of the Grinding Machine······················16
  10. Bearings and Lubricators································18

Appendix:Defects of the Grinding Surface and the Corrections···19

  1. Precautions
  1. Read this Instruction Book before using the grinding machine;
  2. This machine is a precision surface grinding machine, which must be operated by properly trained workers;
  3. Special warnings:
  4. Earth connection of the grinding machine (the yellow-green pair cable) must be ensured;
  5. Reversing the principal axis with the grinding wheel is strictly prohibited;
  6. Using the grinding machine before closing the grinding wheel jacket is strictly prohibited;
  7. Staying or operating the grinding machine in the rotating direction of the grinding wheel is strictly prohibited; and
  8. Touching the working grinding wheel with hands, tools or anything else is strictly prohibited.
  1. Conveyance of the Grinding Machine

The grinding machine had been tested and adjusted to an allowed range of precision through systematic procedures before leaving the factory. Therefore, extra care in the conveyance and installation of the grinding machine is required, and no collision is allowed so as to prevent damages and failures. To be exact:

  1. Conveyance before opening the packing case
  2. Work the operating sides as indicated on the packing case when conveying it with a forklift, and see to it that the center of gravity is well controlled and no collision and damage occurs to the packing case;
  3. Fasten the steel cable to the packing case at points with lifting signs when conveying it with a crane, and have the steel cable’s length well adjusted to ensure the gravity balance of the packing case (e.g. the cable for the heavier end should be shorter);
  1. Conveyance before opening the packing case
  2. See to it that no collision occurs to the machine when conveying it with a forklift so as to prevent damaging the coatings and changing the precision of the grinding machine (see Fig. 1 for more directions on conveying the grinding machine with a forklift);
  3. Fasten the steel cable to the four lifting hooks on the two sides of the machine foundation when conveying it with a crane, keep the center of gravity well controlled, and wrap the lifting hooks with soft materials so as to prevent damaging the coatings and changing the precision of the grinding machine (see Fig. 2 for more directions on conveying the grinding machine with a crane).

Fig 1 Fig2

  1. Specifications
  2. Flatness of the grinding surface: 0.005mm/(200×300mm)
  3. Surface roughness of the grinding surface: Ra0.8
  4. Size of the workbench (L×W): 500×250mm
  5. Horizontal length of travel of the workbench: 600mm
  6. Vertical length of travel of the workbench: 270mm
  7. Maximum distance between the workbench and the center of the principal axis: 465mm
  8. Maximum load capacity of the workbench (with the electromagnetic sucker): 100kg
  9. Width and quantity of the T-shape tank of the workbench (mm×N): 14×1
  10. Vertical traveling speed of the workbench: 5～22m/min
  11. Horizontal handwheel feed of the workbench:

Handwheel/round: 4mm

Dial/measure: 0.02mm

  1. Horizontal automatic feed of the workbench: 0.1～6.5mm
  2. Horizontal fast travel of the workbench: 780mm/min
  3. Rotation speed of the wheel head: 2,850r/min
  4. Vertical-feed of the wheel head:

Handwheel/round: 2mm

Dial/measure: 0.01mm

  1. Aperture of the principal axis grinding wheel: φ31.75mm
  2. Taper of the conical surface of the principal axis grinding wheel: 1:5
  3. Maximum grinding wheel size: φ31.75×φ200×20mm
  4. Power of the wheel head motor: 1.5kw
  5. Power of the oil hydraulic motor: 0.75kw
  6. Power of the cooling motor: 40w
  7. Power of the horizontal drive motor: 6NM
  8. Lubricating oil pump: AC220V
  9. Size of the grinding machine (L×W×H): 1550×1300×1800mm
  10. Minimum operating space of the grinding machine: 2100×1500×1800mm
  11. Size of the packaging: 2050×1450×2000mm
  12. Net weight of the grinding machine: 1,300kg
  13. Gross weight of the grinding machine: 1,500kg
IV.Installation

Installation site

Grinding machine is a high-precision machine tool. It is very important to decide on where it is installed, for its installation site has a remarkable influence over its performance and precision. For this reason, the installation site must be away from vibration sources, such as pneumatic hammer, heavy-duty cutting machine, planing machine and milling machine.

The grinding machine occupies an area of 2300×1500mm.

Ground for installation

Ground for the installation of the grinding machine must be solid and flat, with the concert layer being at least 200mm in thickness. Soft and rough ground can lead to the decline in the precision of the grinding machine, and even the deformation and failure of the grinding machine.

Installation

There are two ways for the installation:

  1. Using L-shape foot screws

See fig. 3 for the positions of the basic screw holes of the foot screws;

See fig. 4 for the sizes of the foot screws and screw holes;

Installation steps: fasten the foot screws to the machine with leaving the screw threads adjustable in a range of at least 30mm; lay down the machine slowly with putting the foot screws into the basic screw holes; filling the screw holes with concrete after the level of the machine is well adjusted; the machine gets ready for use after the foundation becomes solid.

  1. Using foot screws and adjustable screw base

Screw up the foot screws into the screw holes of the machine as tight as possible to achieve the best possible fastening effect;

Lay down the machine slowly with putting the foot screws into the screw holes of the adjustable screw base;

Adjust the level of the machine to complete the installation.

Test Run

Remove the rust proof oil on the machine after it is correctly installed; Fill up the lubricating oil tank with No. 30 lubricating oil into the lubricating oil tank to the rear right of the machine after opening the rear cover board of the machine; rotate the hand wheels in all directions, and travel the wheels to their full range for two to five times to check up their travel smoothness; power on and run the machine if there is no problem found.

Before the test run: fill up the lubricating oil tank with No. 20~30 lubricating oil; connect the oil pipes on the main frame with the lubricating oil tank (Note: the oil pipes should match the directing signs on the lubricating oil tank, otherwise the speed of the vertical travel of the machine cannot be adjusted); dismantle the assemblies of the grinding wheel, and start up the principal axis to see if its rotation direction is correct; power on the hydraulic oil tank pump and cooling water pump to see if their rotation direction is correct; check the magnetization and demagnetization of the electromagnetic sucker; check the performance of the horizontal feed motor; check the performance of the hydraulic system; check if the switch of the oil pressure gauge is fastened up (Note: the speed-adjusting knob should be placed at its lowest level before starting up the vertical travel of the workbench; the speed should be adjusted slowly after the starting up.)

Special Note: the operating oil pressure had been adjusted and tested before the machine left the factory. If there is the need for readjusting it, do the following: adjust the workbench travel speed to its lowest level, loosen the switch of the oil pressure gauge, and turn the oil pressure-adjusting switch of the overflow valve (screw up to increase the pressure, and unscrew to reduce the pressure). The highest oil pressure should not exceed 2.5MPa. After the adjustment is completed, screw up the switch of the oil pressure gauge to finish. Readjusting the oil pressure is not recommended in principle if there is no major failure.

After all the abovementioned checkups are passed, start up and keep running all parts of the machine for fifteen minutes, and power off the machine; then install the examined and balanced grinding wheel on the principal axis and keep running the principal axis motor for five minutes. If there is no problem, trial grinding becomes ready.

V.Mechanical Structure of the Grinding Machine

The machine’s upright column and guide rail are a whole part. The precisely made wheel head travels smoothly and stably, with a hidden motor structure, which makes the look of the machine pleasing to the eyes.

The horizontal and vertical travel mechanisms respectively has a double V-type guide rail and a –V-type guide rail, the advantages of which include good guidance quality, small frictional force, easy and flexible travel, high stability and precision.

Both the horizontal and vertical feeding parts have two kinds of feed mechanisms: hydraulic/motorized feed and manual/handwheel feed, which both are of a high efficiency.

The principal axis is equipped with precision bearings made in Japan, which are featured by its high revolving accuracy, stable performance, low noise level, high-quality grinding surface with a roughness factor Ra lower than 0.8.

The logical control part, which consists of the programmable controller and step motor, facilitates the machine’s automatic feeding mechanism, stepless speed regulation mechanism, and periodic oil supply for the lubricating system.

The automatic feeding mechanism’s highly reliable non-contact output is adaptive to the frequent feeding and reversing operations associated with the grinding of small-sized articles.

The magnetization and demagnetization controlling mechanism’s non-contact output is adaptive to the frequent magnetization and demagnetization operations. It has a short demagnetization period of time, and can prevent the deformation of the electromagnetic sucker and work pieces so that the grinding accuracy of the work pieces is ensured.

VI.Operation of the Grinding Machine

Control Panel

SB1 SB2: front and rear feed switch

SB3: principal axis start-up button

SB4: principal axis stop button

SB5: hydraulic oil pump start-up button

SB6: hydraulic oil pump stop button

SB7: cooling water pump dust collector motor start-up button

SB8: cooling water pump dust collector motor stop button

S1: manual and automatic operation switch

S2: magnetization and demagnetization switch

SB: General stop button

Z: front and rear feed speed modulation

Note:

  1. Switch to magnetization after the machine is powered on so that the principal axis and hydraulic oil pump can be started up.
  2. Switch to automatic operation when automatic feed is needed, and then adjust the feed speed to the lowest level by turning the speed-adjusting knob counter-clockwise, select feed direction (press the button SB1 or SB2) and adjust the feed speed to the required level by turning the speed-adjusting knob clockwise.

Failure Check

In case of failure in automatic feed, first check if the position of the proximity switch is moving. The switch’s examination distance is 2mm. If the switch exceeds its examination distance, adjust to its examination distance and make the examined object’s amplitude of swing (right-left reversing) the same on both the left and right side to the proximity switch.

Balance of the grinding wheel

Use grinding wheel balancer to balance the grinding wheel as follows:

Before balancing the grinding wheel, level the grinding wheel balancer to balance as indicated by Fig. 1;

Place the assembled grinding wheel onto the balancer by using the balance mandrel as indicated by Fig. 2;

Rotate the grinding wheel on the balancer and mark “S” with a chalk as indicated by Fig. 3;

Fasten the first balance weight “G” to the opposite side of “S” as indicated by Fig. 4 (Note: “G” must be unmovable after this step);

Fasten the other two balance weights “K” to any position on the circular arc with an equal distance “a” from “G” as indicated by Fig. 5;

Rotate the grinding wheel by 90° to see if it is well balanced. If not, move the balance weights “K” until the grinding wheel is well balanced on any position as indicated by Fig. 6;

After the grinding wheel is well balanced, keep the grinding wheel rotating at a normal grinding speed without load for five minutes before using it.

Use of the grinding wheel

Before using the grinding wheel, mount the initially balanced grinding wheel onto the principal axis and have it dressed by a wheel dresser to a required precision;

Before mounting the grinding wheel onto the principal axis, wipe up the grinding wheel’s flange pushing hole and the principal axis’s pushing handle, and then push the grinding wheel to the pushing handle and fasten them by screwing up the fixing nuts (unscrew the fixing nuts when dismantling them);

Grinding wheel becomes unbalanced as a result of abrasion. Therefore, it is important not to let out cooling water when the grinding wheel stays still; otherwise, the grinding wheel becomes unbalanced after absorbing water. Before using it, always run the grinding wheel for a few minutes without load to discharge water by making use of the centrifugal force so as to keep its balance.

Dressing the grinding wheel with a dressing (diamond) knife

The grinding wheel can be dressed with the wheel dresser on the electromagnetic sucker or the horizontal wheel dresser on the principal axis seat, the former of which is more usually used. Steps: first fix the travel direction of the workbench, and then rotate the hand wheel;

The grinding wheel can also be dressed with a dressing (diamond) knife. When dressing the grinding wheel this way, make sure the included angle between the wheel and knife is about 15° so as to keep the sharpness of the knife;

When the grinding wheel is used in coarse grinding, dress the wheel by letting the knife touch the wheel fast to achieve a fast dressing effect; when the same grinding wheel is used in precision grinding, dress the wheel slowly for two or three times, with a dressing depth of about 0.01 each time;

Keep the dressing knife cool when using it dressing the wheel, but never do that through shock cooling to prevent the diamond from cracking;

Always begin the dressing from the middle of the grinding wheel, as beginning from the wheel edge where there are more abrasions than the middle will cause considerable pressure to the knife and can lead to cracking of the diamond;

The grinding wheel must be dressed with the wheel dresser on the electromagnetic sucker when it is used in high precision grinding;

In the following figures are the positions of the dressing knife in dressing the grinding wheel (the rotation direction of the grinding wheel is counter-clockwise.)

Fig. 1: the included angle between the wheel and knife should be about 15°;

Fig. 2: the knife should be reversed to keep its sharpness when it is badly abraded;

Fig. 3: the knife works as well as a new one when being reversed;

Fig. 4: the dressing should begin from the middle of the grinding wheel.

Common side abrasions of the grinding wheel:

  1. The contact area between the side abrasions and the work piece is the minimum where the grinding effect and precision is the maximum;
  1. The contact area between the side abrasions and the work piece is relatively small where the grinding effect and precision is relatively high;
  1. The grinding wheel and the work piece contact with each other with a zero included angle, which brings about roughness and unevenness of the grinding surface and even lead to grinding cracks.

Human-computer operational screen of PSG-2550AHDNC surface grinding machine

Instructions: click to select “simplified Chinese” or “English”after entering this machine opening screen, click “JOB MENU” to enter the operational screen of “PROCESSING OPTIONS”.

Instructions: click “MANUAL PROCESSING” to enter the operational screen of manual processing, click “AUTOMATIC PROCESSING” to enter the operational screen of automatic processing, click “BACK” to back to the opening screen.

Instructions: parameter setting of automatic surface grinding. click the numeric frame of “TRANSVERSE FEED AMOUNT OF WORKING PLATFORM” to input the needed feed amount, and then click “enter” to confirm. click the numeric frame of “WORKING PLATFORM FEED TIMES” to input the needed feed times, and then click “enter” to confirm. click the numeric frame of “WORKING PLATFORM FEED SPEED” to input the needed feed speed, and then click “enter” to confirm. click the numeric frame of “GRINDING WHEEL FEED AMOUNT” to input the needed feed amount (0~0.2mm), and then click “enter” to confirm. click the numeric frame of “GRINDING WHEEL FEED TIMES” to input the needed feed times, and then click “enter” to confirm. click the numeric frame of “GRINDING WHEEL FEED SPEED” to input the needed feed speed, and then click “enter” to confirm. click “PROCESSING START” to start the automatic feed procedure, and then the transverse feed of working platform and the grinding wheel downward feed will be started to work according to the established parameters. click “PROCESSINGSTOP” to stop all the automatic feed procedure

Instructions: after entering the manual processing screen, click the numeric frame of “TRANSVERSE FEED AMOUNT OF WORKING PLATFORM” to input the needed feed amount, and then click “enter” to confirm. when you need manual surface grinding, the transverse feed amount of working platform per one time will be feeded according to the established parameters, and will incessantly feed forward or backward, the working platform will reversely feed till reach to the transverse limit switch.