JPH0348022A - Plate-spring type universal joint - Google Patents

Abstract

PURPOSE:To improve durability in the connecting parts of the coupling main body and the intermediate body for improving transmission accuracy by setting the shape and size of respective plate springs constituting the intermediate body so as to have the same shape and size, and by partially welding to each other the outer peripheral end surfaces of the plate springs in the vicinity of the fitting holes. CONSTITUTION:The plate springs 30, 30 constituting the intermediate body are welded in the laminated direction in the end periphery in the vicinity of fitting holes 31. In other words, a part of the end periphery of these plate springs 30, 30 are integrally constituted to each other, and the integrated parts are positioned in the vicinity of a plurality of fitting holes 31, 31 provided in the intermediate body. Thus, in the vicinity of the fitting holes 31, 31 of respective plate springs 30, 30, these plate springs are in such a state that the relative movement has been prevented, and the parts between the fitting holes 31, 31 are in a flexible state. In other words, even in the case of torque transmission in the mode the intermediate body is repeatedly flexed, the parts in the vicinity of the fitting holes 31 in respective plate springs 30 are prevented from being relatively moved.

Description

[Detailed Description of the Invention] [Field of Application and Summary of the Invention] The present invention relates to a universal joint, particularly a leaf spring coupling type shaft joint, which includes a main body of the input joint connected to a human-powered shaft and an intermediate body. By improving the connection structure between the laminated leaf spring group and the connection structure between the main body of the output side joint connected to the output shaft and the laminated leaf spring, the durability of the laminated leaf spring is improved and the transmission performance is improved. It is intended to improve

[Prior art and its problems] As shown in Fig. 7, a leaf spring type shaft joint has an input shaft (10).
The input side joint main body (1) connected to the output shaft (20
) is connected to the output side joint main body (2) and the leaf spring (30
) (30) are connected by a laminated intermediate body (3), and the intermediate body (3) bends in the axial direction in the connected state, but has sufficient rigidity in the rotational direction of the shaft. Therefore, similar to the so-called hook joint (universal joint), the human power shaft (10) and the output shaft (
20) and intersect at a certain angle, torque is transmitted.

However, in this universal joint, the transmitted torque is transmitted through the intermediate body (3
) and the input joint main body (1), and the joint between the intermediate body (3) and the output joint main body (2), and these joint parts are likely to be damaged.

For example, there is a fitting margin between the mounting hole (31) formed in the intermediate body (3) and the mounting bottle (32) as shown in FIG. ) and the seat of the input side joint main body (1) or the output side joint main body (2), in the case of a type in which the fixation is performed by the clamping force between the intermediate body (
3), when an external force is applied in the direction of bending the intermediate body (3), a slippage corresponding to the above-mentioned fitting margin occurs between the leaf springs (30) constituting the intermediate body (3), and this intermediate body (3) However, as shown in the figure, the intermediate body (3) is bent, and the rigidity in the rotational direction of this intermediate body (3) becomes extremely low. In other words, the transmitted torque is significantly reduced. As mentioned above, even if extreme deformation does not occur, when transmitting forward and reverse rotation, there will be a mismatch between the forward rotation transmission torque and the reverse rotation transmission torque, and the transmission performance will be impaired in this respect. Enough is enough.

Further, if the torque transmission state continues in the above-mentioned state, the leaf spring constituting the intermediate body (3) will be damaged.

Therefore, in order to solve this problem, the 9th
The configuration shown in the figure is adopted.

This improved conventional example has a plate spring (30
) (30) Position each other with a hollow pin (40) inserted through the mounting hole (31), and use this hollow pin (40) to connect the intermediate body (3) and the input side joint body (1) or the output side joint body (2).

In this case, since the hollow pin (40) is inserted into the mounting hole (31) of the intermediate body (3) in advance for positioning, the leaf springs (30) forming the intermediate body (3) are prevented from sliding against each other. It is difficult for this to occur.

However, even with this conventional type, its durability is insufficient, and when used for a long period of time, play may occur between the mounting hole (31) of the leaf spring (30) and the hollow pin (40). , and further, the leaf spring (30) is inserted from the periphery of the mounting hole (31).
damage may occur.

This is because if the mounting hole (31) of the leaf spring (30) is formed by punching, a non-smooth fractured surface will occur around the periphery of the mounting hole (31). ) under the condition that the outer peripheral surface and the fractured surface are in contact with each other,
When torque is transmitted with the input joint main body (1) and the output side joint main body (2) intersecting, a slight crack remaining on the fracture surface grows, and eventually this mounting hole (31 )
This is because it will result in damage.

In order to prevent such inconveniences, it is conceivable to perform reaming to remove the non-smooth fractured surface on the periphery of the mounting hole (31) that serves as the insertion portion for the hollow pin (40). In this case, although the above-mentioned inconvenience is resolved, the reaming process becomes extremely troublesome.

Furthermore, even if this is the case, there will be a gap between the outer periphery of the hollow pin (40) and the inner periphery of the mounting hole (31), although it is small, and this gap will correspond to the The plate springs of the intermediate body (3) can move relative to each other by a distance of 1.5 mm, which causes a decrease in durability.

Also, the leaf springs (30) (30) are attached to each other through the holes (31).
As described above, relative movement in the vicinity of , when transmitting forward and reverse rotations, causes a mismatch between the forward rotation transmission torque and the reverse rotation transmission torque, resulting in insufficient transmission performance in this respect.

[Technical Problem] The present invention solves the following problems: “Input side joint main body (1) and output side joint main body (1)
2) are connected by the intermediate body (3) so as to be bendable in a state of preventing relative rotation, and the intermediate body (3)
The connection of the input side joint body (1) and the output side joint body (2) is provided in each joint body using a mounting hole (31) formed through the shaft body in the intermediate body (3). In the universal joint 1, which is inserted through the joint body, the objective is to improve the durability of the joint between the main body of each joint and the intermediate body (3), and to improve the transmission accuracy, and in order to solve this problem, The technical problem with mounting the laminated leaf spring is to maintain the portion near the hole (31) in a state where relative rotation is prevented.

[Means] The technical means of the present invention taken to solve the above technical problem is to set the shape and size of each leaf spring (30) that constitutes the intermediate body (3) to be the same, Spring (30)
1. The outer peripheral end faces of (30) near the random attachment holes (31) are partially welded to each other in the stacking direction.

[Action Co. The above technical means works as follows.

The leaf spring (30) (30) constituting the intermediate body (3) is
In other words, these leaf springs (30) (30) are welded in the stacking direction at the edge near the mounting hole (31).
They are integrally fixed at a part of their edges, and this fixed part is located near the plurality of attachment holes (31) (31) provided in the intermediate body (3). .

Therefore, the mounting hole (31) of each leaf spring (30) (30)
In the vicinity of (31), these relative movements are inhibited, and the portion between these mounting holes (31) (31) is in a freely bendable state. In other words, even when transmitting torque in a manner in which the intermediate body (3) repeatedly bends, each leaf spring (
30) The portion near the mounting hole (31) in (30) will not move relative to each other.

[Effect] Even in a transmission state where the input side joint main body (1) and the output side joint main body (2) repeatedly bend, the leaf springs (30) (30
) in the vicinity of the mounting hole (31) will not move relative to the plate spring (30) constituting the intermediate body (3).
) can be prevented from being bent into a permanently deformed state, resulting in decreased durability and reduced transmission torque. Moreover, torque transmission performance is improved.

[Example] Hereinafter, an example of the present invention will be described based on FIGS. 1 to 6.

In the embodiment shown in FIGS. 1 to 5, the intermediate body (3) is constructed by laminating ring-shaped leaf springs (30) of a constant width, and each leaf spring (30) has a circular shape. Attachment holes (31) are formed at positions that divide the circumference into four equal parts. This leaf spring (30)
is manufactured by punching, but when each leaf spring (30) formed in this way is barrel-finished, the second
As shown in the figure, the attachment hole (31) has a rounded cross-sectional shape by removing the non-smooth surface of the fractured surface.

Therefore, the fine cracks generated during the shearing step of the punching process by press working are removed by the barrel polishing.

The intermediate formed and finished as described above (3
) are stacked, the mounting holes (31) will match each other. Therefore, the intermediate body (3) of the present invention is completed by stacking these leaf springs (30) (30) and welding the edges near the attachment holes (31) (31) to each other.

Note that the following direction was adopted as this welding direction.

First, the leaf springs (30) (30) are stacked in a constant posture, and a jig (J) is used to improve the stacking accuracy. This jig (J) is attached to each leaf spring (30
) mounting hole (31) Shaft body (G) aligned with (31)
(G) protrudes from the substrate (5), and these shaft bodies (G)
A presser plate (51) is attached and fixed to the tip of (G).

Then, as shown in Fig. 4, the shaft (G) of the jig (J)
(G) are inserted into the mounting holes (31) (31), and the plate springs (30) (30) are laminated, and each of the plate springs (30) constituting one intermediate body (3) is made of steel plate. A partition plate (35) having the same shape as the spring (30) is interposed, and pressure is applied between the substrate (5) and the holding plate (51).

As a result, the leaf springs (30) (30) constituting the intermediate body (3) are tightly continuous in the axial direction within the jig (J) with the partition plate (35) in between.

Then, the leaf spring (30) (3) attached to the jig (J)
0) is partially welded around its periphery by laser welding.

In this laser welding, the substrate (5) and the holding plate (51) are
Support both ends of the shaft (50) provided in the mounting hole (3
1) With the end face located on the outer periphery of (31) facing upward, irradiate this end face with a laser beam (R) to partially melt the edge of the leaf spring at the irradiated part, so that the end edges of the leaf spring are connected to each other. Welded by the molten part. At this time, the laser beam (
When running at a constant speed in the axial direction of the jig (J) with respect to R), as shown in the figure, the molten part reached a certain depth and was held in the jig (J). Leaf spring (30) (3
0) is welded in the stacking direction.

Since the partition plate (35) has a low thermal conductivity, this part will not be melted by the laser beam (R), so the leaf spring (30) (30) group constituting the intermediate body (3) is formed by the laser welding described above. Only the parts are welded to each other in the stacking direction.

After performing the above welding work on the outer edge of each mounting hole (31) (31) and removing it from the jig (J), welding will occur on the edge near the mounting hole as shown in Figure 1. An intermediate (3) comprising part (M) is constructed.

This intermediate body (3) is attached to the input side joint main body (1) and the output side joint main body (
When attached to 2), it becomes a leaf spring type universal joint.

In the above embodiment, each leaf spring (30) (30) has a circular annular shape, but as shown in FIG. 5, it may have a rectangular annular shape. Also, in principle, the effects of the present invention will not be affected if the welded part is welded in a direction other than the laser welding in the above embodiment, but in the case of laser welding, the accuracy of the welding depth cannot be controlled. It is easy to use and improves product accuracy.

As shown in Fig. 6, as a connection structure between the laminated leaf spring (3) and the input side joint main body (1) or the output side joint main body (2), a hollow pin (4o) with a flange is inserted into the mounting hole ( 31), press the base end of this hollow pin (40) into the washer (42), and tightly fit said (42) into the concave part of the flange part (F) of the main input/output side joint. and said flange part (F
) For installation through the hollow pin (40), insert the screw (N) into the hollow pin (40).
A configuration in which the screw is screwed into the acid threaded portion (43) can be adopted.

In this case, compared to the conventional example described above, the length of the mounting screw is shortened, and the thickness of the joint between the laminated leaf spring (3) and the flange part (F) is reduced, making the mounting difficult. This eliminates the need for a through hole or the like for the tightening nut to protrude through the flange portion (F) located on the opposite side of the head of the screw (N).

[Brief explanation of drawings]

FIG. 1 is a perspective view of an intermediate body (3) according to an embodiment of the present invention. Figure 2 is an explanatory diagram of the leaf spring (30), Figure 3 is the jig (J)
2. FIG. 4 is an explanatory diagram of the welding process, FIG. 5 is an explanatory diagram of another example of the intermediate body (3), FIG. 6 is a sectional view of essential parts of a universal joint using this intermediate body, Figures 7 to 9 are explanatory diagrams of conventional examples, in which 1)... Input side joint main body 2)... Output side joint main body 3)... - Laminated leaf spring 31)... Installation Hole M)...Welded part

Claims (1)

[Claims] The input side joint main body (1) and the output side joint main body (2) are combined with one or more intermediate bodies (
3), the intermediate body (3) is connected so as to be able to swing relative to each other in a state where relative rotation is prevented, and the structure of the connecting portion between the intermediate body (3), the input side joint body (1), and the output side joint body (2) is changed according to each of the above-mentioned. In a universal joint in which a mounting shaft provided on the main body of the joint is inserted into a mounting hole (31) formed through the intermediate body (3), each leaf spring (
30) are set to have the same shape and size, and the outer peripheral end surfaces of these leaf springs (30) and the end surfaces near the mounting hole (31) are partially welded to each other in the stacking direction. Type universal joint.