JPS5945815B2 - Method for manufacturing a lever with a pin in a mechanical speed governor for an internal combustion engine - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a mechanical speed governor for a fuel injection pump for an internal combustion engine, and more particularly to a method for manufacturing a lever with a pin used therein.

Generally, this type of engine type governor uses various levers with pins, which communicate with each other to form a link.

This link transmits the movement of the control block related to engine speed to the control rack.
The load-related movement of the adjusting lever is also transmitted to the control rack.

For example, in FIGS. 1 and 2, the lower end of a guide lever 3 is connected to a control block 2 that moves under the centrifugal force of a weight 1.
consists of a pin-equipped lever with a pin 4 connected to its lower end,
It is rotatably connected to a hole in the control block 2 by a pin 4.

Also, the intermediate portion of the floating lever 5 is connected to the intermediate portion of the guide lever 3 to form a link, or the floating lever 5 is also constituted by a lever with a pin, and is rotatably connected to the guide lever 3 by the pin 6. be done.

Furthermore, the connection between the floating lever 5 and the shackle 7, the connection between the shackle 7 and the control rack 8, the support of the guide lever 3 and the tension lever 9 to the case 10, the support of the adjusting lever 11 to the case 10, and the adjustment lever 11 and the floating lever 5 are also communicated with the same structure.

By the way, in order to obtain good governor operation, the various pin-equipped levers that make up such a speed governor must be lightweight, and the pins that connect to other levers must have sufficient durability. The lever must have abrasion resistance, and the lever must have appropriate rigidity.
Also, high accuracy of the perpendicularity between the lever and the pin is required.

Furthermore, from the standpoint of safety, it is required that the pin and lever never separate from each other, and furthermore, for practical purposes, it is required that it be possible to manufacture a small lever with a pin.

Generally speaking, the method of connecting a pin to a lever-like object is as follows:
The most widely used method is to insert the pin into the hole in the lever and then swage its head. In this case, in order to apply the swage load to the pin, the perpendicularity between the pin and lever must be adjusted. Also, if the load is large, there is a risk that pins or levers may bend.

Therefore, this caulking method is not often adopted for levers with pins for speed governors, and instead, the brazing method for pins and levers has been widely used in speed governors.

However, even in this conventional joining method by brazing, the pin and lever are heated to a high temperature that exceeds Iooo°C during brazing, so the thermal distortion at this time actually causes the pin and lever to become perpendicular. It was put away.

Furthermore, in order to improve the wear resistance of the pin, carburization is applied as a surface hardening method, and at this time also 9000G
In order to receive more heat, it was again subjected to the heat change due to carburization, further reducing the squareness.

Therefore, in order to correct the perpendicularity between the pin and the lever, the lever is carbon-proofed and the flatness of the lever is corrected to improve the accuracy of the perpendicularity, but this does not work in practice and requires a lot of man-hours. Because of this, mass production was not possible.

There is also a device in which the lever and the pin part are integrally manufactured by casting, but in this case, the casting itself is difficult and requires a lot of man-hours.

Moreover, it was difficult to reduce the weight, and due to the characteristics of the speed governor, the inertia of the link was poor, the operation was slow when the rotation speed and load changed, and the speed control tracking ability was poor.

Another drawback was that the vibration resistance of the pin portion was weak.

SUMMARY OF THE INVENTION The present invention aims to solve the above-mentioned drawbacks of the conventional art by providing a method for caulking a pin and a lever using a very small load without causing any risk of deformation of the lever and pin.

The present invention will be explained in detail below with reference to the drawings.

In the method of manufacturing various pin-equipped levers for mechanical speed governors shown in FIGS. 1 and 2, the present invention provides a through hole 21 at an appropriate position in the lever 20, chamfers one end of this hole 21, and A chamfered portion 22 having θ of approximately 60° to 90° is provided.

At this time, the inner diameter of the hole 21 is finished to fit approximately JIS H7.

Machining and chamfering of the hole 21 can be performed by a well-known method.

Thereafter, the lever 20 is subjected to surface hardening treatment by tuft-dite or carburizing to produce a single lever.

Apart from manufacturing this lever alone, the pin 30 to be connected to the hole 21 of the lever 20 is provided with an insertion part 31 at the end, as shown in FIG. A flange portion 32 having a large diameter is also provided to form a stepped portion 33.

The insertion part 31 is a part inserted into the hole 21 of the lever 20,
Its length is slightly longer than the length of the hole 21 of the lever 20, and its outer diameter is finished to fit JIS h7.

Further, a bored hole 34 is provided in the end surface of the insertion portion 31, and the open end thereof is chamfered to form a chamfered portion 35 having a right angle θ of about 60° to 90°.

The inner diameter of the bored hole 34 is such that the thick portion left on the outside of the hole 34 is constricted (pushed outward) by a relatively small load, and the constricted portion has sufficient strength. Please choose accordingly.

Note that these processes can be performed by known methods.

Subsequently, the pin 30 is subjected to a surface hardening treatment by tuftedite or carburization on the connection portion with another lever located closer to the center than the flange portion 32 .

At this time, at least the insertion portion 31 and the bored hole 34 are carburized and are not subjected to surface hardening treatment to facilitate subsequent caulking.

Note that this surface hardening treatment can also be performed prior to forming the boring hole 34.

Next, the lever 20 and pin 30 made in this way are joined together, but at this time, first insert the insertion part 31 of the pin 30 into the hole 21 of the lever 20 on the side opposite to the side where the chamfered part 22 of the hole 21 is provided. Insert from.

This insertion is performed until the step 33 of the pin 30 contacts the surface of the lever 20, causing the end of the insertion portion 31 of the pin 30 to protrude slightly from the hole 21 of the lever 20.

Then, as shown in FIG. 5, a jig 40 is applied to the central end surface of the flange 32 of the pin 30, and in this state, a punch 41 with a conical tip is pressed into the boring hole 34 of the pin 30 with an appropriate load. Press it against the recess 35, caulk the end of the pin 30, and push it outward.

The part pushed outward by this caulking is pressed against the chamfered part 22 of the lever 20, and the pin 30 is pressed between it and the step 33.
is coupled to the lever 20.

In this caulking process, a bored hole 34 is provided in the pin 30, and the outer edge left by the formation of this hole 34 is pushed diagonally outward with a punch 41, so for example, such a hole may not be provided. The load during caulking can be significantly reduced compared to when caulking.

Therefore, it goes without saying that the lever 20 and the pin 30 will not be deformed by the load during caulking, and the lever 20
The perpendicularity of the pin 30 with respect to the pin 30 does not become distorted.

In addition, in the conventional brazing method, the lever 20 and pin 30 are damaged due to thermal distortion.
However, the above caulking method is not affected by such heat.

Moreover, since the lever 20 and the pin 30 are surface-hardened in advance, once the pin 30 and the lever 20 are connected at an accurate right angle, this right angle will not change after that.

Now, in the mechanical speed governor shown in Figs. 1 and 2,
If there is an error in the perpendicularity between the pin and the lever in various types of levers with pins, even if the error in each lever is small, the individual errors will add up in the overall ring that combines these levers. This results in a large error and greatly deteriorates the performance of the speed governor.

Therefore, it is important to accurately maintain the squareness of each pinned lever, and the method of the present invention makes this possible as described above.

Of course, by appropriately selecting the wall thickness of the caulked portion, the caulked portion can have sufficient strength.

Next, the chamfered part 22 provided at one end of the hole 21 of the lever 20 increases surface pressure by a kind of wedge action by pressing the caulked part of the pin 30 against the chamfered part 22, Increase the bonding area.

Therefore, the connection between the pin 30 and the lever 20 is strengthened, and in particular, the resistance when the pin 30 rotates relative to the lever 20 is increased.

Furthermore, according to the method of the present invention, other properties required of a pin-equipped lever of a mechanical speed governor, namely, light weight and
It is possible to fully satisfy requirements such as miniaturization and providing pins with sufficient wear resistance.

Thus, in the present invention, it is possible to provide a lever with a pin that is optimal for a mechanical speed governor.

In the present invention, the pin itself may be hollow instead of having a bored hole in the pin.

[Brief explanation of the drawing]

Fig. 1 is a block diagram of a general mechanical speed governor, Fig. 2 is a plan view showing the structure of the link shown in Fig. 1, Fig. 3 is a sectional view of the main part of the lever in the present invention, FIG. 4 is a partial sectional view of the main part of the pin according to the present invention, FIG. 5 a is a front view of the lever and pin joined together by the method of the present invention, and FIG. It is. 20... Lever, 21... Hole, 22.
・・・・・・Take part, 30... Pin, 31...
...Insertion part, 33...Stepped part, 34...
...bore-shaped hole.

Claims (1)

[Claims] 1. A step of providing a hole in a suitable position of the lever and chamfering one end of the hole, and an insertion part longer than the hole of the lever and a part longer than the insertion part at the end of the pin to be connected to the hole of the lever. a stepped portion whose outer diameter increases, and a step of providing a bored hole in the end face of the insertion portion; a step of applying a surface hardening treatment to the connection portion of the pin with other levers other than the insertion portion; After all of these steps, insert the insertion part of the pin into the hole of the lever from the side opposite to the chamfered side and press the stepped part against the surface of the lever, and in this state, A mechanical system for an internal combustion engine, comprising the step of caulking an outer edge of a bored hole outward and pushing it wide, and pressing the caulked portion against a chamfered portion of the lever to couple the pin to the lever. A method of manufacturing a lever with a pin in a speed governor.