JPH0224611Y2 - - Google Patents

Description

[Detailed Description of the Invention] Industrial Application Field The present invention relates to a cutting fluid injection mechanism suitable for internal grinding of a deep hole penetrated by an internal grinder.

Prior Art In the center chuck of an internal grinder, grinding fluid is generally supplied from the grinding wheel side. For this reason, when grinding a deep-hole workpiece, it is difficult to sufficiently supply the grinding fluid to the grinding point.

Problems that the invention aims to solve Lack of grinding fluid causes grinding burn, reduced grinding efficiency, and poor machining accuracy, and there has been a great demand for improvement. For this reason, it is possible to realize a solution for a deep through hole that does not have a first stop.

Means for Solving the Problem A grinding fluid supply pipe member 13 having check valves 14, 15, 16, 17 which are always closed at the tip thereof is provided at the center of the main shaft 2, and a sleeve is provided at the center of the chuck 3 fitted on the main shaft. 6 is replaceably provided, and the sleeve is movable in the axial direction, has a center hole 7c with which the forward end is regulated and serves as a grinding fluid supply path, and a contact portion which opens the check valve by retreating. The sleeve also has a built-in spring 10 that always biases the center in the forward direction, and when a workpiece is gripped, a check valve is opened and grinding fluid can be injected from the center side. This is how it was done.

Embodiments Hereinafter, embodiments of the present invention will be described based on the drawings. A known diaphragm chuck 3 is fitted concentrically to the shaft end of a hollow main shaft 2 inserted into a headstock 1 of a known internal grinding machine. This diaphragm chuck 3 has gripping claws 5 radially attached to three equal parts on the outside of a diaphragm 4 whose outer periphery is fixed, and a balance weight is attached to the inside. A piston rod of a cylindrical hollow piston fitted in a donut-shaped cylinder (not shown) in the chuck 3 pushes against the inner side of the center edge of the diaphragm 4. The center through hole 3a of the diaphragm chuck 3 has large diameters 6a, 6 on the front and rear opening sides.
A flanged sleeve 6 having a center hole 6c indicated by b is fitted concentrically at the flange portion so as to be replaceable with bolts.

A center 7 having a large diameter base 7a and a flange 7b in the middle is inserted into the hole 6c of the sleeve 6 in a floating state with a considerable amount of play. A grinding fluid passage 7c is formed in the center of the center 7, and a large diameter hole 7d is continuously formed in the base 7a. A spherical retainer 8 is fitted into the bottom of the large-diameter hole 7d, with a center hole 8a formed in the center so as to connect to the grinding fluid passage 7c, and several notches 8b formed in the axial direction at the rear end. There is. This center 7 is urged in the forward direction by a compression spring 10 interposed between a lid 9 bolted to the rear end of the sleeve 6 and a flange 7b, so that the flange 7b of the center 7 sleeve 6
It is in contact with the bottom of the large diameter hole 6b. In addition, the lid body 11 which is fastened to the bottom of the large diameter hole 6a on the front side of the sleeve 6 with a bolt has a tapered hole formed in the center.
There is a gap suitable for air blowing between the tip and the tip. A passage 6d for sending pressurized air into this air blowing gap is provided up to the rear end of the sleeve 6.

Further, a grinding fluid supply pipe 13 held by a support plate 12 is inserted through the center of the main shaft 2, and a check valve cylinder 14 having a center hole 14a at the tip of the supply pipe 13 is inserted.
is screwed on. The check valve cylinder 14 urges the sphere 16 toward the center 7 side by the spring 15, and the sphere is screwed into the female thread at the mouth of the check valve cylinder 14 and is inserted into the valve seat 17, which has a hole in the center into which the sphere retainer 8 is loosely inserted. 16 is pressed. O-rings are installed in areas where it is necessary to prevent leakage and infiltration of grinding fluid, air, etc.
A seal is attached, and the grinding fluid is supplied from a supply source (not shown) through the hole 13a of the grinding fluid supply pipe 13, and the pressurized air is supplied from the supply pipe 18 passing through the center hole of the main shaft 2 through the hole in the support plate 12 to the passage of the sleeve 6. 6d.

The workpiece W has a deep hole penetrated through it, and a jig 19 is used to hold it in the correct position using surfaces Wa and Wb to be ground at the back of the hole.
The workpiece is grasped by a robot, loader, etc., and the workpiece is inserted and carried in and out. The jig 19 is provided with a flange portion 19a, the end surface of which is attached to the flange of the sleeve 6 and comes into contact with the end surface of a stopper 20 disposed at three equal positions between the gripping claws 5 during chucking. The position of the workpiece W in the axial direction is determined. A grindstone 23 is attached to the tip of a grindstone shaft 22 that is rotated by a high-frequency motor built in an internal grindstone spindle 21 provided on a grindstone head movable in X and Z axes (not shown).

Operation When the workpiece W having a deep hole penetrated therethrough is determined, a center unit consisting of a suitable sleeve 6, center 7, and stopper 20 is selected and attached to the chuck 3. The check valve cylinder 14 is inserted into the large-diameter hole in the base 7a of the center 7, and the center 7 is pushed by the spring 10 to be at the forward end.
6 is in contact with the valve seat 17 and closes the check valve. In the chuck 3, pressure fluid is sent to the rear chamber of a cylinder (not shown), and the diaphragm 4 is pushed by the forward movement of the piston, so that the grip claws 5 are in an open state.

The jig 19 into which the workpiece W is inserted and supported is positioned substantially concentrically with the front surface of the chuck 3 by a robot, and pressurized air is sent from the supply pipe 18 and blown around the tip of the center 7 from the passage 6d to perform air blowing of the center. When the jig 19 is moved toward the spindle 2, the tip of the center 7 fits into the hole of the workpiece W, and the center 7 is pushed back. Center 7 with this retreat
The ball presser 8 presses the ball 16 against the force of the spring 15 to open the valve seat 17. When the flange 19a of the jig 19 comes into contact with the end face of the stopper 20 attached to the sleeve 6, the axial position of the workpiece W can be accurately determined.

Pressure fluid to a cylinder (not shown) of the chuck 3 is switched to the front chamber, the piston is retracted, the diaphragm 4 returns by its own elasticity, and the gripping claws 5 grip the workpiece W from three directions. The robot retreats in the axial direction while holding the jig 19. When gripping is completed, high-pressure cutting fluid flows from the hole 13a of the cutting fluid supply pipe 13 to the hole 14a of the check valve cylinder 14 and the ball holder 8.
The passage 7c of the center 7 passes through the hole 8a from the notch 8b of
This grinding fluid is injected into the inside of the workpiece W through the tip hole. The whetstone head is controlled and the whetstone 2
3 is inserted into the hole of the workpiece W, a cutting feed is applied to grind the grinding surface Wa with the conical portion, and then it is retreated and the grinding surface Wb is ground. At this time, the grinding fluid blown out from the center of the center 7 is injected from the side closer to the grinding surface at the back, so that it is sufficiently supplied to the grinding surface. When the predetermined grinding is completed, the robot holding the jig 19 is moved from the retreat position and inserts the jig 19 into the hole of the workpiece W. The gripping claws 5 of the chuck are opened, and the robot receives the workpiece and transports it to the next process. When the workpiece W is removed, the center 7
is pushed to the forward end by the force of the spring 10, and the ball presser 8 is separated from the ball 16. The force of the spring 15 presses the sphere 16 against the valve seat 17 to close the valve port.

Effects As detailed above, the present invention has a grinding fluid passage in the center of the center and a supply pipe with a check valve at the rear of the center so that when the workpiece is gripped, the check valve is opened when the center retreats and supply is supplied from the center side. With this structure, sufficient grinding liquid is injected into the grinding part during deep hole grinding of a through hole, so that the grinding accuracy is further improved and the grinding efficiency is also much higher. Furthermore, the center unit including the sleeve, center, and spring can be easily replaced to suit the workpiece, allowing for a wide range of applications. Furthermore, the tracking accuracy can be improved by air blowing at the center.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal sectional view of the mechanism of the present invention, and FIG. 2 is a diagram showing the grinding state. 2...Main shaft, 3...Chuck, 5...Gripping claw,
6... Sleeve, 7... Center, 8... Ball holder, 13... Cutting fluid supply pipe, 14... Check valve tube, 10, 15... Spring, 16... Sphere, 1
7... Valve seat, 19... Jig, 20... Stopper.

Claims (1)

[Claims for Utility Model Registration] (1) A grinding fluid supply pipe member having a check valve at its tip which is always closed is provided at the center of the main shaft, and a sleeve is provided in a replaceable manner at the center of the chuck fitted to the main shaft; The sleeve has a built-in center which is movable in the axial direction and has a center hole which is regulated at the forward end and serves as a grinding fluid supply path, and has an abutting part that opens the check valve when the sleeve is moved backward. The center chuck also has a built-in spring that always biases the center in the forward direction, and a check valve is opened when gripping a workpiece so that the grinding fluid can be injected from the center side. Injection mechanism. (2) The grinding fluid injection mechanism for a center chuck according to claim 1, wherein the sleeve is provided with an air passage for air blowing at the tip of the center.