JPH0538409U - Positioning structure for machine parts - Google Patents

Abstract

(57) [Abstract] [Purpose] To provide a positioning structure for mechanical parts, which can stably position an article with a knock pin, can well eliminate stress concentration in a pin hole, and can smoothly drive a pin. .. [Composition] An air vent hole communicating with the bottom of the pin driving hole is formed in the knock pin.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a mechanical part positioning structure used for positioning a mechanical part when the mechanical part is attached to a machine body.

[0002]

[Prior Art]

 When attaching a machine part to the machine body, the machine part may be positioned on the machine body with a knock pin, and the machine part may be attached to the machine body by welding or the like under this positioning.

In the positioning of mechanical parts by means of this knock pin, generally, a bottomed positioning hole is provided on the main body side and a through hole positioning hole is provided on the component side, and the knock pin is driven across these holes and holes. There is.

In this case, when the entire inner circumference of the hole and the entire outer circumference of the pin are brought into close contact with each other, air is compressed between the bottom of the hole and the tip of the pin together with the driving of the pin, and the knock pin is driven by the compressed air. May become difficult, or the compressed air may expand due to the heat generated when welding the parts or the heat received depending on the operating conditions of the machine, causing the pins to suddenly detach. The air vent is provided on the article side or the knock pin side.

However, when an air vent is provided on the article side, depending on the structure of the article, it may be necessary to provide an air vent hole in a large-thickness portion, which makes the processing troublesome and also increases the mechanical strength of the article. Decline is also a problem.

On the other hand, in the case where the air vent is provided on the knock pin side, there is no such problem, and conventionally, the knock pin outer surface is cut out, and a gap is formed between the pin and the pin hole to communicate from the bottom of the pin hole to the outside. It is known to bleed air.

[0007]

[Problems to be solved by the device]

 Until the part is fixed to the main body, the knock pin also receives shearing force and bending moment due to the lateral load acting relatively between the main body and the part, as in a normal pin. However, when the outer surface of the knock pin is cut out as described above, a non-contact portion is generated between the knock pin and the pin hole, and the state between the knock pin and the pin hole becomes uneven in the circumferential direction. Since the response state between the knock pin and the pin hole differs depending on the direction of the lateral load, the strain under the stress becomes excessive in the direction with the lateral load, and it is difficult to guarantee strict positioning. Sometimes.

[0008] Further, in the inner peripheral edge of the pin hole, a portion that is not compressed due to non-contact with a portion that is strongly compressed by a knock pin and causes a stress concentration, so that the operating conditions of the device, machine, etc. Depending on the situation, stress corrosion of the inner peripheral edge of the pin hole may be a problem.

Furthermore, when notching the outer surface of the pin is performed by grinding such as a grinder, a burr is likely to occur, and the removal of the burr is troublesome, which hinders the driving of the pin.

An object of the present invention is to provide a positioning structure for mechanical parts, which can stably position an object with a knock pin, can well eliminate stress concentration in a pin hole, and can smoothly drive a pin. To do.

[0011]

[Means for Solving the Problems]

 The mechanical component positioning structure of the present invention is characterized in that an air vent hole is formed in the knock pin, the air vent hole extending to the bottom of the pin driving hole.

[0012]

[Action]

 Since the entire outer periphery of the pin and the entire inner periphery of the pin hole can be contacted uniformly, the stress state of the pin can be the same regardless of the direction of lateral load, and stable positioning without directionality can be guaranteed. Further, since the stress acting on the inner circumference of the pin hole can be made uniform in the circumferential direction and the stress concentration can be sufficiently prevented, the stress corrosion and the like on the inner circumference of the pin hole can be well eliminated. Furthermore, since the outer surface of the pin is not required to be cut, burr does not occur, and the air is not compressed to remove air from the air vent hole, so that the pin can be driven smoothly. You can

[0013]

【Example】

 An embodiment of the present invention will be described below with reference to the drawings. 1 is a sectional view showing an embodiment of the present invention, FIG. 2 (a) is a longitudinal sectional view showing the knock pin in FIG. 1, and FIG. 2 (b) is a lateral sectional view.

In FIGS. 1 and 2 (a) and (b), 1 is a parallel pin, which is made of stainless steel or the like. 2 is an air vent hole penetrating into the pin 1 from the lower end to the upper end of the pin 1. The ratio d / D between the inner diameter d of the air vent hole and the outer diameter D of the pin is 0. It is set to 5 or more.

In FIG. 1, 31 is a bottomed hole provided in the main body 3, 41 is a through hole provided in the component 4, and when the knock pin 1 is driven into the hole 41 and the hole 3, a part is inserted into the main body 3. The product 4 is being positioned.

During the driving of the pin, since the bottom portion 32 of the pin hole 31 is opened to the outside through the air vent hole 2 in the pin 1, the driving of the pin 1 can be smoothly performed without compressing the air. obtain. Further, even if the air in the pin hole bottom portion 32 is heated by welding the component 4 to the main body 3 after the pin is driven in, the pin 1 does not pop out.

In FIG. 1, when a lateral load F is relatively applied between the main body 3 and the component 4, the pin 1 is subjected to bending moment and shearing force by the couple F · F. Since the contact state of 1 with the pin hole 31 and the pin hole 41 is uniform in the circumferential direction and there is no directivity, the stress against the lateral load F can be the same regardless of the direction of the lateral load. Therefore, the temporary fixing of the component 4 until the component 4 is fixed to the main body 3 by welding or the like can be performed in the same manner with respect to the lateral load without directionality, and the position positioned by the pin 1 can be stabilized. Can hold

Further, the distribution of the stress generated in the inner peripheral edge of the pin hole 31 and the pin hole 41 by driving the pin 1 can be made uniform in the circumferential direction of the pin. Therefore, the stress concentration can be eliminated and the stress caused by the stress concentration can be eliminated. The progress of corrosion can also be suppressed.

In the knock pin used in the present invention, in addition to a circular hole, a square hole, a triangular hole, a hexagonal hole or the like can be used as the air vent hole in the pin. In addition to the circular pin, a square pin can be used as the pin 1.

[0020]

[Effect of the device]

 The positioning structure for the mechanical parts of the present invention is configured as described above, and air can be smoothly discharged, and stable positioning can be guaranteed regardless of the direction of the lateral load acting on the pin. It is possible to prevent stress damage at the early stages of pin holes due to stress corrosion, etc., and to smoothly insert pins.

[Brief description of drawings]

FIG. 1 is a sectional view showing an embodiment of the present invention.

FIG. 2A is a vertical sectional view showing one of knock pins used in the present invention, and FIG. 1B is a horizontal sectional view thereof.

[Explanation of symbols]

 1 pin 2 air vent hole 31 pin hole 32 pin hole bottom 41 hole

Claims (1)

[Scope of utility model registration request] 1. A positioning structure for a mechanical component, wherein an air vent hole communicating with the bottom of a pin driving hole is formed in the knock pin.