JPS6315083B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a lever mechanism that generates direct motion of a linear motion mechanism by rotating around a single fulcrum, and particularly relates to an improvement in the structure of a lever action section.

A linear motion mechanism, for example, a drawbar that grips or unlocks a tool at the lower end of the spindle by moving the drawbar installed in the spindle of a machine tool's spindle head up and down, uses a lever mechanism to move the drawbar up and down. A structure that generates operating power is often adopted. In such a screw mechanism, an engagement ring engaged with the linear motion mechanism is provided, and two oval grooves extending in the circumferential direction are formed at opposing positions separated by 180 degrees on the outer periphery of the engagement ring. A working pin provided at one arm end of the screw mechanism is fitted into the oval groove, a cam follower that engages with the swing drive cam is provided at the other arm end, and a swing fulcrum is provided between the ends of both arms. By providing
A structure is adopted in which the direct motion of the direct motion mechanism is generated via the working pin and the engagement ring as the lever mechanism turns. In such a screw mechanism, as mentioned above, the engagement ring in the action point structure is structured to have an elongated groove formed in advance to provide a free movement gap for the action pin. It is formed by a complicated milling process. In addition, in the case of the drawbar direct drive mechanism provided on the spindle head of the machine tool mentioned above, both the engagement ring and the working pin are made of strong metal materials such as iron, so the elliptical groove of the engagement ring is A high metallic noise is generated when the working pin moves loosely and comes into contact with the arc end.

SUMMARY OF THE INVENTION Accordingly, it is an object of the present invention to provide a working pin engagement device for a screw mechanism which is improved so as to facilitate machining of the engagement ring and eliminate metallic noise of the screw mechanism.

According to the present invention, one arm end has a screw acting part that is engaged with an engagement ring attached to a linear motion mechanism, and the other arm end has a turning force receiving part. In the lever mechanism that rotates around the fulcrum between both arms,
A circumferential groove is provided on the outer periphery of the engagement ring, and an elastic body is implanted in the circumferential groove, thereby forming two oblong holes facing each other on the outer periphery of the engagement ring, and There is provided a working pin engagement device for a lever mechanism, characterized in that working pins protruding from the lever working portions of the arm ends are fitted into two oval holes.
According to the structure in which a circumferential groove is formed in the engagement groove as described above, the circumferential groove can be easily formed by lathe processing, and the length can be increased by implanting an elastic body in the circumferential groove. Since the circular hole is formed, the noise generated by the contact between the working pin and the elastic body can be kept at a quiet level compared to conventional metal noise. Furthermore, if the elastic body is made of an inexpensive rubber material, noise can be eliminated and costs can be reduced as well. Hereinafter, the present invention will be described in detail based on embodiments shown in the accompanying drawings.

Figure 1 shows an example of a structure in which a lever mechanism is used to linearly move a drawbar provided in the main shaft of a machine tool.
has an arm 12, and one end 14 of this arm 12 has an engagement ring 1 that engages with the tip of a linear drive drawbar 16.
8 and the other end 20 of arm 12 has a cam follower 24 which engages a pivot cam 22 fixed to the body of the machine tool. more arms 12
has a pivot point 26 located midway between both ends 14 and 20, and this pivot point 26 is fixed to the spindle head 30 via a support 28. The drawbar 16 is fitted into the main shaft 32 and moves linearly upward or downward in FIG. Since the fastening is released, the tool can be removed from the lower end of the spindle 32. Now, when the spindle head 30 moves upward from the position shown in FIG.
The cam follower 24 rides on the top of the swing cam 22, thereby causing a swing movement of the arm 12 in the direction of arrow "A" about the fulcrum 26, thus causing the cam follower 24 provided between the end 14 and the engagement ring 18 to rotate in the direction of arrow "A". A downward force is applied to the drawbar 16 via the action point structure 34, and the drawbar 16 moves downward. Also,
When the spindle head 30 moves downward so that the cam follower 24 of the arm 12 descends from the top of the swing cam 22, the contracted disc spring stretches and a lifting force acts on the drawbar 16, causing the arm 1 of the lever mechanism 10 to
2 rotates in the direction of arrow "B", and the drawbar 16
moves upward.

Now, FIGS. 2 and 3 are a plan view showing the configuration of the conventional application point structure 34' in the lever mechanism 10, and a side view taken from the arrow-line direction in FIG. As is clear from Figure 3, the engagement ring 18
Oval grooves 40 are formed by milling at two opposing positions spaced apart by approximately 180 degrees on the outer periphery of a, and the end portion 14 of the lever mechanism 10 ( The working pin 42 protruding from the fork-shaped embodiment) is fitted, and at this time the working pin 42
An appropriate amount of movement is allowed in the circumferential direction of the engagement ring 18a. However, according to such a conventional application point structure 34', as described at the beginning, the processing method of milling the two oblong grooves 40 on the circular outer circumferential surface is cumbersome and causes a relatively high manufacturing cost. Regarding the function of the screw, when the arm 12 pivots, the working pin 42 collides with both arcuate ends of each oval groove 40, producing a metallic noise.

In view of these drawbacks of the conventional application point structure 34', the present invention particularly improves the structure of the engagement ring as described below.

Now, FIGS. 4 and 5 are a plan view and a fourth
FIG. 3 is a side view taken along the arrow-line in the figure. Same 4th
In the action point structure portion 34″ shown in FIGS.
The structure of the end portion 14 of the arm 12 and the working pin 42 is no different from the structure of the conventional working point structure 34' described above. However, in the present invention, the annular groove 44 extending over the entire outer circumference of the engaging ring 18b is formed in advance in a metal processing step. This annular groove 44
The machining method requires only the design groove depth and groove width to be obtained by lathe machining, so the machining process itself is extremely easy, the manufacturing cost is significantly reduced, and the surface finish and accuracy are good. can be kept. Now, in the annular groove 44 of the engagement ring 18b, two elastic members 46 are embedded in an arc shape in the circumferential direction, and between the ends of these elastic members 46, the length of the above-mentioned conventional engagement ring 18a is Two oblong holes 48 corresponding to the circular grooves 40 are formed. A working pin 42 protruding from the end 14 of the arm 12 is fitted into these two oval holes 48. If the elongated hole 48 into which the working pin 42 is fitted is formed between the two circumferential ends of both elastic members 46 in this way, the working pin 42 can be inserted into the elongated hole 48 during the lever action.
Even when the elastic member 46 and the working pin 42 are moved loosely, the elastic member 46 and the working pin 42 collide with each other, so that metal noise can be prevented from occurring. Moreover, if a rubber material is used for the elastic member 46, the cost of the elastic member 46 itself can be kept low. Therefore, in addition to reducing the processing cost of the circumferential groove 44, the processing cost of the engagement ring 18b can be reduced compared to the conventional method. The cost can be kept lower than that of the combined ring 18a. In addition, in order to embed the elastic member 46 in the circumferential groove 44, there are two methods: adhesively fixing the elastic member 46 using an adhesive;
An appropriate method may be selected from among various methods such as a method of fixing using a screw member and a method of fixing by casting.

As is clear from the above description, according to the present invention, the working pin engagement device of the screw mechanism can be realized as a structure that is inexpensive and prevents generation of metallic noise by the improved structure of the engagement ring. If a lever mechanism is used in a machine tool, it can reduce factory noise and contribute to environmental improvement.

[Brief explanation of the drawing]

Figure 1 is a schematic diagram of the mechanism in which a lever mechanism is used to generate linear motion of a drawbar on the main shaft of a machine tool, and Figures 2 and 3 are conventional configurations of the structure of the action point of the lever mechanism. 4 and 5 are a plan view and a side view showing an embodiment of the present invention in the structure of the action point of a lever mechanism; FIG. 10...Lover mechanism, 12...Arm, 14, 20...
... End of arm, 26 ... Fulcrum, 18, 18a, 18
b... Engagement ring, 42... Working pin, 44... Circumferential groove, 46... Elastic member, 48... Oblong hole.

Claims (1)

[Scope of Claims] 1 One arm end has a lever action part that is engaged with an engagement ring attached to the linear motion mechanism, and the other arm end has a turning force receiving part, and the above-mentioned In a lever mechanism that rotates around a fulcrum between both arms, a circumferential groove is provided on the outer periphery of the engaging ring, and an elastic body is implanted in the circumferential groove, so that the outer periphery of the engaging ring is A working pin engagement device for a lever mechanism, characterized in that two oval holes facing each other are formed, and a working pin protruding from the lever action part of the arm end is inserted into the two oval holes. . 2. The working pin engagement device for a lever mechanism according to claim 1, wherein the elastic body is made of a rubber material.