JPH066756U - Elastic shaft - Google Patents

Abstract

(57) [Abstract] [Purpose] It is an object to provide an elastic shaft having three-step nonlinear torsional characteristics. [Structure] This elastic shaft includes a first shaft 1 having a pair of facing surfaces 12 and 13 forming a shaft hole 11, and a pair of back facing surfaces 22 and 2.
The second shaft 2 having 3, the facing surfaces 12, 13 and the back surface 22,
It is composed of a first rubber elastic body sandwiched by 23 and a second rubber elastic body 4 fixed to the second shaft 2. This second
The rubber elastic body 4 includes a first contact portion 4a having a thickness t2 that is vulcanized and bonded to one back surface 22 and a second contact portion 4b that has a thickness t3 and is fixed to the other back surface 23. Become. The second shaft 2 relatively rotates in the direction of arrow S1 or S2.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to an elastic shaft. This elastic shaft can be applied to, for example, an intermediate shaft of a steering mechanism of a vehicle.

[0002]

[Prior art]

 Conventionally, the elastic shaft shown in FIG. 6 is known. The elastic shaft is inserted through the shaft hole 101 of the first shaft 100 and has a pair of facing surfaces 102 that are parallel to each other and forms a shaft hole 101, and faces each facing surface 102 of the first shaft 100. A second shaft 200 having a pair of back surfaces 202 parallel to each other, a first rubber elastic body 300 vulcanized and bonded to the back surface 202 of the second shaft 200, and a first rubber elastic body 300. The second rubber elastic body 400 is arranged in series in the axial direction and is vulcanized and bonded to the back surface 202 of the second shaft 200.

Then, the second shaft 200 is press-fitted into the shaft hole 101 of the first shaft 100, the first rubber elastic body 300 is sandwiched between the opposing surface 102 and the back surface 202, and the second rubber elastic body 400 is formed. A gap M is formed between and the opposing surface 102. In use, the first shaft 100 is connected to one of the drive shaft and the driven shaft and the second shaft 200 is connected to the other of the drive shaft and the driven shaft. Then, when torque is transmitted from the drive shaft to the driven shaft, relative rotation in the circumferential direction occurs between the first shaft 100 and the second shaft 200, whereby the first rubber elastic body 300 first moves in its thickness direction. Is compressed to. When the relative rotation angle between the first shaft 100 and the second shaft 200 further increases, the second rubber elastic body 400 comes into contact with the facing surface 102 of the first shaft 100 and is compressed in the thickness direction.

Such a torsional characteristic of the elastic shaft exhibits a non-linear characteristic as schematically shown in FIG. 7, has a rising region P1, and has a first region P2 obtained by the first rubber elastic body 300. In addition to the first rubber elastic body 300, there is a second area P3 after the rising area P1 obtained by the action of the second rubber elastic body 400. That is, it exhibits a two-stage torsion characteristic.

[0005]

[Problems to be solved by the device]

 However, the above-mentioned elastic shaft is not always sufficient to meet the recent sophistication of the required characteristics of the elastic shaft. In addition, there is a problem that the torsional characteristics suddenly rise. Therefore, when the elastic shaft is applied to the intermediate shaft of the vehicle steering mechanism, the feeling of the steering wheel is not sufficiently satisfactory.

The present invention is a further improvement of the conventional elastic shaft described above, and an object thereof is to provide an elastic shaft having three-step torsional characteristics.

[0007]

[Means for Solving the Problems]

 The elastic shaft of the present invention includes a first shaft having a pair of parallel facing surfaces that are connected to one object and form a shaft hole, and a first shaft that is connected to another object and is inserted into the shaft hole of the first shaft. The first shaft and the second shaft are sandwiched between a second shaft having a pair of back-face surfaces parallel to each other facing each other of the shaft and a facing surface of the first shaft and a back-face surface of the second shaft. The first rubber elastic body, which is compressed by the relative rotation in the circumferential direction, is positioned in series with the first rubber elastic body in the axial direction, is fixed to the back surface of the second shaft, and is in contact with the facing surfaces of the first shaft. And a second rubber elastic body facing each other in a contactable manner. The second rubber elastic body has a first contact portion having a predetermined thickness fixed to one of the back surfaces of the second shaft, and the second rubber elastic body. It is characterized in that it is fixed to the other back-facing surface and comprises a first contact portion and a second contact portion having a different thickness.

[0008]

[Action]

 The operation of the elastic shaft of the present invention will be described along with its usage. In use, the first axis is connected to one object and the second axis is connected to another object. Then, with the rotation between both objects, relative rotation in the circumferential direction of the first axis and the second axis occurs. Due to the relative rotation, the first rubber elastic body is compressed. When the relative rotation angle between the first shaft and the second shaft further increases, one of the first contact portion and the second contact portion of the second rubber elastic body contacts the opposing surface of the first shaft and compresses. To be done.

When the relative rotation angle further increases, both the first contact portion and the second contact portion of the second rubber elastic body come into contact with the opposing surface of the first shaft and are compressed.

[0010]

【Example】

 Hereinafter, embodiments of the elastic shaft of the present invention will be described with reference to FIGS. The elastic shaft is composed of a first shaft 1 made of metal, a second shaft 2 made of metal, a first rubber elastic body 3, and a second rubber elastic body 4. The first shaft 1 has a pair of parallel facing surfaces 12, 13 forming a shaft hole 11 having an opening 10. The other end 1b of the first shaft 1 is swingably connected to a yoke 15 forming a universal joint via a pin 1e. One end 2a of the second shaft 2 is inserted through the shaft hole 11 of the first shaft 1 and has a pair of parallel back facing surfaces 22 and 23 facing the facing surfaces 12 and 13 of the first shaft 1, respectively. Hold. A spline 25 is formed on the other end 2b of the second shaft 2.

As shown in FIG. 2, the first rubber elastic body 3 has a thickness t1 and is vulcanized and adhered to the rearward facing surfaces 22 and 23 of the second shaft 2, respectively. The first rubber elastic body 3 is press-fitted into the shaft hole 11 and is compressed in the thickness direction by the facing surfaces 12 and 13 of the first shaft 1 and the rearward facing surfaces 22 and 23 of the second shaft 2. . The first rubber elastic body 3 maintains the coaxiality between the first shaft 1 and the second shaft 2.

As shown in FIG. 1, the second rubber elastic body 4 is positioned in series in the axial direction with the first rubber elastic body 3 and is vulcanized and bonded to the back surfaces 22 and 23 of the second shaft 2, respectively. There is. The second rubber elastic body 4 faces the facing surfaces 12 and 13 of the first shaft 1 via a gap M so as to be able to come into contact with each other. The second rubber elastic body 4 is vulcanized and adhered to the first abutment portion 4a that is vulcanized and bonded to one back surface 22 of the second shaft 2 and the other back surface 23 of the second shaft 2. It has a second contact portion 4b. The thickness of the first contact portion 4a is indicated by t2. The thickness of the second contact portion 4b is indicated by t3, which is thinner than the first contact portion 4a (t2> t3).

Further, in the present embodiment, as shown in FIG. 3, the second abutting portion 4b ′ integrally formed with the first abutting portion 4a is vulcanized and bonded to the one back surface 22. There is. Further, a first contact portion 4a 'integrally formed with the second contact portion 4b is vulcanized and bonded to the other back surface 23. That is, as can be understood from FIG. 3, the second rubber elastic body 4 has an asymmetrical shape with respect to the virtual line W1 passing through the axis. The second rubber elastic body 4 is made of the same material as the first rubber elastic body 3.

In use, the first shaft 1 is connected to one of the drive shaft and the driven shaft, and the second shaft 2 is connected to the other of the drive shaft and the driven shaft. In this state, when the drive shaft rotates in the forward direction, the second shaft 2 relatively rotates in the direction of arrow S1 which is the circumferential direction. Then, as can be understood from FIG. 2, while the portion 3a of the first rubber elastic body 3 is compressed by the back surface 22 and the facing surface 12, the portion 3a of the other first rubber elastic body 3 is arranged in the back The surface 23 and the facing surface 13 are compressed.

When the relative rotation angle of the second shaft 2 in the arrow S1 direction further increases, the first contact portion 4a of the second rubber elastic body 4 faces the first shaft 1 as can be understood from FIG. It abuts the surface 12 and is compressed. When the relative rotation angle in the direction of arrow S1 further increases, not only the first contact portion 4a but also the second contact portion 4b contact the opposing surface 13 of the first shaft 1 and are compressed.

A case where the drive shaft rotates in the reverse direction and rotates in the direction of arrow S2 will be described. In this case, the second shaft 2 relatively rotates in the direction of arrow S2. Then, as can be understood from FIG. 2, the portion 3b of the one first rubber elastic body 3 is compressed by the back surface 23 and the facing surface 13, and the portion 3b of the other first rubber elastic body 3 is arranged in the back direction. The surface 22 and the opposing surface 12 are compressed.

When the relative rotation angle of the second shaft 2 in the direction of the arrow S2 further increases, as can be understood from FIG. 3, the first contact portion 4a ′ of the second rubber elastic body 4 becomes the first shaft 1 as shown in FIG. It abuts against the opposing surface 13 of and is compressed. Further, when the relative rotation angle in the direction of the arrow S2 increases, not only the first contact portion 4a 'but also the second contact portion 4b' contact the opposing surface 12 of the first shaft 1 and are compressed.

The torsional characteristic of the elastic shaft having such a structure exhibits a non-linear characteristic as schematically shown in FIG. 4, has rise regions F1 and F2, and has a first rubber elastic body 3. The region F3, the second region F4 after the rising region F1 obtained by the action of the first contact portion 4a of the second rubber elastic body 4 in addition to the first rubber elastic body 3, the first rubber elastic body 3, and the second region F4. In addition to the first contact portion 4a, it has a third region F5 after the rising region F2 obtained by the action of the second contact portion 4b. That is, it exhibits a three-stage twisting characteristic.

When the above elastic shaft is applied to the intermediate shaft of the steering mechanism of the vehicle, the first region F3 becomes the flutter reduction region, the second region F4 becomes the steering stability region, and the third region F4 becomes the steering stability region. The area F5 becomes the durability ensuring area. As described above, the torsional characteristic of the present embodiment has the two-stage rising regions F1 and F2, which is advantageous for avoiding a sudden rising, and the handle feeling is improved.

Other Examples Another example of the present invention is shown in FIG. The constitution of this example is also basically the same as that of the above-mentioned embodiment, and basically the same effects are obtained. However, the second rubber elastic body 4 includes a first contact portion 4a having a predetermined thickness t4 that is vulcanized and bonded to one of the back facing surfaces 22 of the second shaft 2, and the other back facing surface of the second shaft 2. The second contact portion 4b is vulcanized and adhered to the surface 23 and has a thickness t5 smaller than that of the first contact portion 4a.

That is, as can be understood from FIG. 5, the second rubber elastic body 4 has an asymmetrical shape with respect to the imaginary line W2 passing through the axis in the cross section in the direction perpendicular to the axis.

[0022]

[Effect of device]

 According to the elastic shaft of the present invention, the first rubber elastic body is compressed by the relative rotation of the first shaft and the second shaft in the circumferential direction. When the relative rotation angle between the first shaft and the second shaft further increases, one of the first contact portion and the second contact portion of the second rubber elastic body is compressed. When the relative rotation angle further increases, both the first contact portion and the second contact portion are compressed. Therefore, a three-step twist characteristic can be obtained. Moreover, there is an advantage that it is possible to avoid a sudden rise.

[Brief description of drawings]

FIG. 1 is a sectional view of an elastic shaft.

FIG. 2 is a sectional view taken along line II-II of FIG.

FIG. 3 is a sectional view taken along line III-III in FIG.

FIG. 4 is a graph schematically showing twist characteristics.

5 is a sectional view taken along line III-III of FIG. 1 according to another example.

FIG. 6 is a sectional view of a main part of an elastic shaft according to a conventional example.

FIG. 7 is a graph schematically showing a twisting characteristic according to a conventional example.

[Explanation of symbols]

In the figure, 1 is a first shaft, 11 is a shaft hole, 12 and 13 are facing surfaces,
Reference numeral 2 is a second shaft, 22 and 23 are back surfaces, 3 is a first rubber elastic body, 4 is a second rubber elastic body, 4a is a first contact portion, and 4b is a second contact portion.

Claims (1)

[Scope of utility model registration request] 1. A first shaft having a pair of opposing surfaces that are parallel to each other and are connected to one object to form a shaft hole, and a first shaft that is connected to another object and is inserted into a shaft hole of the first shaft. A second shaft having a pair of parallel back-facing surfaces facing each other of the first shaft, and the first shaft and the second shaft sandwiched between the facing surface of the first shaft and the back-facing surface of the second shaft. A first rubber elastic body that is compressed by relative rotation of the shaft in the circumferential direction; and a first rubber elastic body that is positioned in series with the first rubber elastic body in the axial direction and is fixed to the back surface of the second shaft. A second rubber elastic body facing the facing surface so as to be able to come into contact with the second rubber elastic body, the second rubber elastic body having a predetermined thickness fixed to one of the back surfaces of the second shaft. And fixed to the other dorsal surface of the second shaft, the first shaft
An elastic shaft comprising a contact portion and a second contact portion having a different thickness.