JPS62801Y2 - - Google Patents

Description

[Detailed Description of the Invention] Technical Field The present invention relates to an improvement of a tailstock of a grinding machine that presses the end face of a thin-walled workpiece during processing.

Background of the Technology When grinding a thin workpiece W1 as shown in Fig. 1, the collector chuck 1 is used to avoid deformation of the workpiece.
cannot be grasped with very strong force. Therefore, in order to supplement the gripping force, the end face of the workpiece is pressed and ground using, for example, a T-shaped pusher 2 mounted on the end face of the tailstock shaft. But rough, rough,
During dense spark-out grinding, if a hydraulic or spring pressure type tailstock with constant thrust is used to push the workpiece, distortion will remain in the workpiece that has been distorted even slightly by the thrust during dense grinding and spark-out, and the cylindricity and trueness will deteriorate. High precision roundness processing was impossible. Therefore, during fine grinding and spark-out, the pusher 2 is moved back to eliminate the thrust, and when the pusher 2, which was pushing the end surface during rough and coarse grinding, is moved back for fine grinding, the conventional tailstock is not used. Since the shaft is completely retracted, when grinding a similar stepped workpiece W2 as shown in Fig. 2 with the same grindstone 1, there is an inconvenience that the T-shaped pusher 2 interferes with the step of the grindstone and cannot be used. It was hot.

Purpose Therefore, the present invention has been made in view of the above, and aims to provide a tailstock that can process similar stepped workpieces with the same grindstone and is suitable for high-precision machining.

Solution The present invention interposes a 4-port, 3-position switching valve in the drive circuit of the tailstock shaft, which is moved forward and backward by hydraulic drive, and has a position that eliminates the hydraulic pressure in the circuit, so that when the hydraulic pressure disappears, the tailstock shaft A spring member and a positioning member are provided for retracting the position by a certain distance.

Embodiments Hereinafter, embodiments of the present invention will be described based on the drawings. A tailstock shaft 3 has a T-shaped pusher 2 attached to its tip and is supported on a tailstock 4 so as to be able to slide freely in the axial direction.
The piston rod 7 and the connecting plate 8 are integrally connected to each other. Therefore, the tailstock 3 is moved forward and backward relative to the workpiece by the piston 6. A flange 9 is provided in the middle of the tailstock shaft 3, and a spring pressure adjustment nut 10 screwed into a screw 3a carved in the rear end and a stepped hole 4a into which the flange 9 is fitted are inserted from the rear side. A compression spring 12 is interposed between the insertion end determined by the inserted flange 11a and a spring receiver 11 which is movable to the rear side, and constantly urges the tailstock shaft 3 rearward.

This spring receiver 11 is connected to both chambers 5a and 5 of the cylinder 5.
It also serves as a stopper that causes the tailstock shaft 3 to move backward by a certain amount when the oil pressure in b is exhausted, and causes the flange 9 to come into contact with the tailstock shaft 3. A small cylinder 13 is formed at the center of the end face of the chamber 5a on the side of the workpiece of the cylinder 5, and a small rod 14 of the piston 6 is fitted into the chamber 5a at the end of the stroke, so as to prevent the tailstock from moving at the forward end of the stroke. At the same time, the end face of the small cylinder 13 determines the forward end position of the tailstock shaft. cylinder 13
A one-way valve 16 and a variable throttle 17 are connected in parallel to the oil passage 15 so as to restrict the flow rate to the oil drain side. It is connected to the oil passage 18 of the cylinder chamber 5a and to the A port of the 4-port 3-position electromagnetic switching valve 19. On the other hand, in the oil passage 20 of the chamber 5b of the cylinder 5, a pressure reducing valve 21 and a one-way valve 22 are connected in parallel, and the pressure is reduced to a constant pressure on the supply side. It is connected. The 4-port 3-position switching solenoid valve 19 is connected to the chambers 5a and 5b of the cylinder 5 in a neutral position so as to eliminate hydraulic pressure.

Next, the effect will be explained. Holding the thin-walled stepped workpiece W1 in the collect chuck 1, the electromagnetic switching valve 19
When the position is changed to cylinder 5 of tailstock 4,
Oil whose pressure is constantly reduced by a pressure reducing valve 21 is supplied from an oil passage 20 to the chamber 5b. The piston 6 advances, the piston rod 7 and the connecting plate 8 advance the tailstock 3, and before the forward end it is decelerated by the cylinder 13 and small rod 14, and the pusher 2 moves the end face at a slow speed to prevent the workpiece W1 from moving. to help grip the pressed workpiece W1. The stepped grinding wheel of the angle slide grinder moves forward and rough grinding is performed by the plunge cut, and when the rough grinding is completed by a sizing device (not shown) and fine grinding begins, the electromagnetic switching valve 19 is switched to the position and the chambers 5a, 5
The oil b is discharged from the oil passages 18 and 20 and reaches the tailstock shaft 3.
Eliminate the axial thrust acting on the Therefore, the tailstock shaft 3 is moved back by the force of the spring 12, and the flange 9 is positioned as shown in FIG. 3 by the spring receiver 11 which also serves as a stopper, and the pusher 2 is separated from the end surface of the workpiece W1 by a certain amount. This amount of separation is determined in advance so that the movement of the spring receiver 11 into and out of the grinding wheel is adjusted in advance so as not to interfere with the steps of the grindstone for grinding other workpieces. When the tailstock shaft 3 is retracted by a certain amount and reaches a fixed size through fine grinding, spark out is performed and the grinding wheel is retracted, the solenoid valve 19 is switched to the position and pressure oil is sent to the oil passage 18 to move the piston 6. make it retreat. Along with this, the flange 9 of the tailstock shaft 3 pushes out the spring receiver 9 and the tailstock shaft 3 waits at the rearward end.

Effects As detailed above, the present invention is provided with a switching valve that has a position that eliminates the hydraulic pressure for moving the tailstock shaft equipped with a pusher on the end face of a thin-walled workpiece back and forth, and when the hydraulic pressure is exhausted, the tailstock shaft is moved back and forth. A spring and positioning member are installed to move the shaft back a certain amount and separate the pusher from the end face of the workpiece, so the end face is not pushed during close grinding or spark-out, allowing high-precision machining of cylindricity and roundness. be able to. In addition, since the presser metal is retracted by a certain amount, it does not interfere with other stages of the grindstone used to process similar stepped workpieces, making it possible to process similar workpieces with the same grindstone, saving time and labor during setup changes. can improve work efficiency.

[Brief explanation of the drawing]

1 and 2 are diagrams showing the processing state of a similar stepped workpiece, and FIG. 3 is an explanatory diagram of the tailstock shaft. 2... pusher, 3... tailstock shaft, 5... cylinder, 11... spring receiver, 12... spring, 19...
4 port 3 position solenoid switching valve.

Claims (1)

[Scope of utility model registration request] Roughen the thin-walled workpiece held by the collector chuck.
In a tailstock that supports a tailstock shaft with a pusher attached to the tip that presses the end surface of the workpiece during rough grinding, a position where the hydraulic pressure of the drive device is removed from the circuit of the hydraulic drive device that moves the tailstock shaft forward and backward. A spring member is interposed between the tailstock shaft and the tailstock to separate the pusher from the end surface of the workpiece when the hydraulic pressure of the drive device disappears. A special core characterized in that the tailstock is provided with a tailstock shaft retreat restricting member for stopping the pressed pusher at a certain position, thereby eliminating thrust to the end face of the workpiece during close grinding and spark-out. Push stand.