JPS624424Y2 - - Google Patents

Description

[Detailed description of the invention] (Conventional field) The present invention relates to a hydraulic shock absorber for a processing machine, in particular,
The present invention relates to a hydraulic shock absorber for a processing machine that is inserted between a processing machine main body and a cutting tool support mechanism.

(Prior Art) The seat surface of the valve seat in the cylinder head of an internal combustion engine is generally required to have high roundness and concentricity with the stem hole of the valve guide, and various processing methods have been used to achieve this requirement. The applicant has also filed a patent application in 1982.
31937 and Japanese Patent Application No. 56-51162, etc., a processing device as shown in FIG. 1A has been proposed.

This device is equipped with a reamer 1 in the center for finishing the stem hole of a valve guide g, and a blade holder a equipped with a cutter c such as a cutter for machining a valve seat Vs on the outer periphery of the center, and a universal joint attached to a spindle s. On the other hand, a ring-shaped support plate P is slidably suspended from a guide bar G extending forward from a multi-axis head H. is provided with a support cylinder d equipped with three or more support pins b that move back and forth in the radial direction and are locked in contact with the circumferential surface of the blade holder a to maintain that state. , insert the reamer 1 into the stem hole of the valve guide g by advancing the multi-axis head H while rotating the spindle s, and move the reamer 1 while adjusting it to the stem hole position as shown in FIG.
When the blade has sufficiently followed the stem hole, each of the plurality of support pins b in contact with the circumferential surface of the blade holder a is locked in that state by hydraulic pressure, and the front and rear of the blade c are connected to the valve guide g and supported. pin b
While maintaining the roundness and concentricity with the stem hole, the valve seat is fixed with the cutter c.
Vs is made to be machined and also the valve seat
When the multi-axis cylinder H moves backward after completing the predetermined machining for Vs, a hydraulic circuit mechanism (not shown) responds to open the oil chamber located on the back of the support pin b and move the support pin b outward. The blade is moved to release the state of support from the blade holder a so that the blade can be moved to the rear of the blade c.

However, with such a structure, if there is not much difference between the outer diameter of the cutter c and the outer diameter of the cutter holder a, if the processing machine body is rapidly retreated after processing to shorten the processing time, the valve The blade c, which has retreated along the axis of the guide g, comes into contact with the support pin b, which is released from hydraulic pressure and moves slowly backward, resulting in mutual damage.

(Purpose) The present invention was made to solve such problems, and its purpose is to reduce the relative movement between the main body and the support member at the beginning of the movement of the processing machine main body. It is an object of the present invention to provide a new hydraulic shock absorber capable of buying time required for a support member to release a cutter holder, etc., and capable of retracting a processing machine main body at high speed without damaging the device.

(Structure) Therefore, details of the present invention will be described below based on illustrated embodiments.

FIG. 2 shows an outline of the device of the present invention applied to a processing device for a valve seat surface of an internal combustion engine, and FIGS. 3 and 4 show its details, respectively.

In the figure, numerals 1 and 2 are the front and rear cylinders that constitute the oil chamber attached to the center of the support plate P, and the front cylinder 1 is located on the work side.
is formed so that its inner diameter is approximately equal to or slightly larger than the outer diameter of the piston 5, which will be described later, and the rear cylinder 2 is located on the multi-axis head H (processing machine main body) side.
is formed to have an inner diameter somewhat larger than that of the front cylinder 1. Inside the cylinder, which has a step at the boundary between these two cylinders 1 and 2 and whose overall length is longer than the stroke of the multi-axis head H, is a rod whose one end is fixed to the multi-axis head H. 3 passes through the rod 3, and a piston 5 is attached to the rod 3 so as to be located at the forefront of the front cylinder 1 when the multi-axis head H advances to the machining position.

This piston 5, together with the cylinders 1 and 2, functions as a doss pot, that is, it is constructed so that it encounters a small resistance when moving to a processing position and a large resistance when moving backward. That is,
In this embodiment, a piston body 51 having a large number of holes 52 around its periphery is fixed to the rod 3, and the holes 52... A wave washer 55 abuts against a ring-shaped check valve 53 having an orifice 54 so as to close it, and is supported by a lock nut 56.
When the multi-axis head H moves forward toward the machining position, the liquid in front of the piston 5 passes through the hole 52 in the piston body 51 and flows out from between the piston body 51 and the check valve 53. When the liquid flows out to the rear of the piston 5 without resistance and the multi-axis head H moves backward, the liquid at the rear of the piston 5 is subjected to a flow contraction effect by the orifice 54 provided in the check valve 53 and flows through the hole in the piston body 51. 5
2 to the front of the piston 5 to create a small resistance when the multi-axis head H moves forward.
It is configured to provide a large amount of resistance when moving backward.

In addition, as an example, there are 8 holes around the piston body 51.
The check valve 53 is provided with several holes 52 at equal intervals.
If four orifices 54 are provided at uneven intervals,
As shown in FIG. 5, a shock absorber piston can be constructed in which one orifice 54 always communicates with the hole 52 of the piston body 51 no matter how the check valve 53 rotates.

In the embodiment described above, when the multi-axis head H is advanced toward the processing position (leftward in the figure), the piston 5 fixed to the rod 3 also moves from the rear cylinder 2 to the front cylinder 1 side. During this forward movement, the check valve 53 provided at the rear of the piston body 51 separates from the rear surface of the piston body 51, so the piston 5 moves forward without any resistance, and the cutting tool c comes into contact with the valve seat Vs. In this state, it reaches near the front end of the front cylinder 1 which has a small diameter.

When the required machining for the valve seat Vs is completed and the multi-axis head H moves to the backward stroke, the front cylinder 1
Along with this, the piston 5, which was located near the front end of the piston 5, also starts moving rightward in the figure. However, in this stroke, the check valve 53 comes into close contact with the rear surface of the piston body 51 and closes the hole 52, so the piston 5 has a narrow clearance between the inner wall of the front cylinder 1 and the sum of the diameter of the orifice 54. A corresponding damping force is generated and the displacement within the front cylinder 1 is small due to the large resistance.
Therefore, when the multi-axis head H continues to retreat, the piston 5 causes the support plate P to retreat through the front cylinder 1 against the spring e, and during this small relative movement, the support pin b is moved outward. to free the blade holder a and buy time.

When the multi-axis head H continues to retreat further and the piston 5 eventually disengages from the small diameter front cylinder 1, the clearance between it and the rear cylinder 2 increases rapidly.
Along with this, the resistance also decreases, so the support plate P, which had previously continued to retreat following the piston 5, is urged by the spring e and moves to the left in the figure, protruding onto the surface of the jig J. The series of strokes ends when the guide post K (Fig. 1) is contacted.

(Effects) As described above, according to the present invention, the blade support member is attached to the tip through a cylinder whose inner diameter is gradually increased in the backward direction of the processing machine body, and a piston that is subjected to the resistance of the fluid during backward movement. Since the processing machine main body equipped with a bearing member and the bearing support member equipped with a bearing member are combined, even if the processing machine main body is rapidly retreated after processing,
At the beginning of the backward movement, the piston, which is integral with the processing machine body, moves the bearing support member backward through the cylinder due to its resistance, and the slight relative movement between the processing machine body and the bearing support member during this period causes the bearing to move backward. It is possible to buy time for the member to sufficiently release the blade support member, thereby preventing damage caused by contact between the bearing member and the blade.

Moreover, the subsequent backward movement of the processing machine body allows the piston integrated with it to be moved to the large diameter part of the cylinder, so that the bearing support member can be quickly moved to its original position when the cutter support member is separated from the bearing member. It can be returned to normal state and ready for the next operation.

[Brief explanation of the drawing]

Figures 1A and 1B are partially cutaway side views showing before and after processing in a processing device for valve seats for internal combustion engines equipped with self-aligning bearings, and Figure 2 is a partially cutaway side view showing the processing state of the valve seat for an internal combustion engine equipped with a self-aligning bearing. The schematic configuration diagram, Figure 3, is
A partially cutaway side view of a device showing an embodiment of the present invention;
FIG. 4 is a perspective view of a piston applied to the above device, and FIGS. 5A and 5B are diagrams showing the arrangement relationship between the piston and the holes in the check valve. 1, 2... Cylinder, 3... Rod, 5... Piston, 51... Piston body, 53... Check valve, a... Cutler holder, b... Support pin, c... Cutler, g... Valve. Guide, H...Multi-axis head, P...Support plate, s...Spindle, Vs...Valve seat.

Claims (1)

[Scope of utility model registration request] The above-mentioned processing machine has a main body of the processing machine, which has a cutter support member at its tip and moves forward and backward relative to the workpiece, and a bearing member which approaches and separates from the circumferential surface of the cutter support member to support and release the support member. a bearing support member disposed to be movable back and forth while receiving a biasing force in the forward direction of the main body; A sealed cylinder whose size is increased in stages, and a piston which is fixed to a part of the processing machine main body and is slidably disposed within the cylinder so as to receive a large fluid resistance when the processing machine main body retreats. Hydraulic shock absorber for processing machines.