JPH01199026A - Clutch device - Google Patents

Abstract

PURPOSE:To perform shifting of inputs between first and second drive shafts, by a method wherein an inclined cam surface is formed on the outer surface of a clutch inner wheel, and two rolling bodies and a spring are contained in a wedge-shaped space formed between the outer surface and the inner surface of a clutch outer wheel. CONSTITUTION:A cylinder surface 21 is formed on the inner surface of a clutch outer wheel 11, the outer surface of a clutch inner wheel 12 is formed in the shape of a polygon, and the plane thereof forms a cam surface 22. Two rolling bodies 25 and 25 ', held by a holder 15, and a spring 27 are mounted in a wedge- shaped space 23 formed with the cam surface 22 and a cylinder surface 21. In this constitution, the holder 15 is coupled to a first drive shaft, the inner wheel 12 to a driven shaft, and the outer wheel 11 to a second drive shaft. In this constitution, since when torque is below a set value, a clutch is not actuated, a rotation force is transmitted from the first drive shaft to the driven shaft, but when exceeding the set value, the clutch is actuated, and the rotation force is transmitted from the first and second drive shafts to the driven shaft.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a clutch device, and particularly to a clutch device suitable for an electric power steering device.

[Conventional technology]

A general configuration of an electric power steering device is shown in FIG. 14. In this device, when the steering wheel 1 is rotated to the right or left, torque is generated on the steering wheel shaft 3 due to resistance from the wheels 2. This torque is detected by a sensor 4 provided on the handle shaft 3, and a motor 6 is driven through a control device 5. Is the drive shaft of motor 6 a deceleration IQ? The pinion 8 of the handle shaft 3 is connected to the pinion 8 of the handle shaft 3, and the wheels 2 are steered via a rack 9 that meshes with the pinion 8 of the handle shaft 3. This allows one wheel to be steered with very little steering force.

[Problem to be solved by the invention]

However, in such an electric power steering device, the control device 5. If an abnormality occurs in the drive system including the motor 6 and reducer 7 and these do not operate, the reducer 7 and motor 6 are connected to the handle shaft 3, so
There is a problem in that the manual steering force becomes excessive, making it virtually impossible to steer the vehicle.

Therefore, a method is known in which a clutch device 10 is interposed between the reducer 7 and the pinion 8.

Although an electromagnetic clutch can be used as the clutch device 10 in this case, it has the disadvantage of being too large to obtain the required transmission torque. Further, when a dog clutch is used, there are problems such as a large force being required for positioning the mesh and releasing the mesh under load.

The problem with this invention is that the first drive shaft and the second drive shaft
An object of the present invention is to provide a small-sized clutch device with high transmission reliability that can mechanically switch and transmit two inputs to a driven shaft without external control.

[Means to solve the problem]

In order to solve the above problems, in the present invention, a cylindrical surface is formed on one side of the inner diameter surface of the clutch outer ring and an outer diameter surface of the clutch inner ring assembled inside the outer ring, and an inclined cam surface is provided on the other side. A pocket is provided in the cylindrical retainer assembled between the clutch outer ring and the clutch inner ring at a position corresponding to the volume space formed by the cylindrical surface and the inclined cam surface, and two rollers are installed in this pocket. The retainer accommodates a moving body and a spring that presses the rolling element in opposite directions to the wall surfaces facing each other in the circumferential direction of the pocket, and the retainer is attached to one of the clutch outer ring and the clutch inner ring on the side having the inclined cam surface. A torque setting elastic member that engages with the member with a clearance in the rotational direction and adjusts to a neutral position of the clearance in the rotational direction and elastically deforms until the clearance in the rotational direction disappears when the set torque is exceeded is provided between the two engaging members. Furthermore, in the neutral position, the rolling elements housed in the pockets of the retainer do not engage with either of the narrow portions at either end of the cubic space.

In order to facilitate manufacturing, a cylindrical surface is formed on the inner diameter surface of the clutch outer ring, a cam surface is formed on the outer diameter surface of the clutch inner ring, and the clutch inner ring and the retainer are engaged with a rotational clearance. With.

It is preferable to connect the clutch inner ring and the retainer with a torque setting elastic member. In this case, a torsion bar can be employed as the torque setting elastic member.

In addition, in order to increase the capacity of the clutch device, the spring housed in the pocket is formed of a leaf spring, and a slit is provided in the length direction of the leaf spring into which a part of the rolling element fits, and the leaf spring is bent. - a first pressing piece that presses one of the rolling elements of the pair, an inclined piece on both ends of the pressing piece, and the other rolling element pressed on both ends of the inclined piece. It is preferable to have a configuration in which a second pressing piece portion is provided.

(Operation) The retainer of the clutch device configured as described above is connected to the first drive shaft, the member of the clutch outer ring and the clutch inner ring on the side having the inclined cam surface is connected to the driven shaft, and the cylindrical member is connected to the driven shaft. If the member on the side having the surface is connected to the second drive shaft, when the torque is less than the set torque, the torque setting elastic member has little deflection and is at a substantially neutral position with respect to the clearance in the rotational direction.
The rolling elements housed in the pockets of the retainer are located in the wide part of the space formed by the cylindrical surface and the inclined cam surface, and the clutch does not operate, causing them to rotate from the first drive shaft to the driven shaft. transmit power. When the set torque is exceeded, the retainer largely deflects the torque setting elastic member, causing the retainer to rotate relative to the clutch outer ring and the clutch inner ring until there is no gap in the rotational direction, and the retainer rotates into the narrow parts at both ends of the cubic space. When the moving body is pressed, the clutch is activated, and rotational force can be transmitted from the first and second drive shafts to the driven shaft.

In addition, when a clutch device configured in this manner is used in an electric power steering device, the retainer is connected to the handle shaft, and the member of the clutch outer ring and the clutch inner ring on the side having the inclined cam surface is connected to the pinion shaft. and the member having the cylindrical surface is connected to the motor. This results in
When the steering wheel operating force is less than the set torque, the manual operating force is transmitted from the handle shaft to the pinion shaft, and when the steering wheel operating force exceeds the set torque, the clutch is activated between the clutch outer ring and the clutch inner ring. , motor driving force is transmitted to the pinion shaft. This allows the wheels to be steered with very little steering force.

In the unlikely event that an abnormality occurs in the drive system including the motor and it does not operate, the handle shaft is rotated and the retainer rotates relative to the clutch outer ring and the clutch outer ring from the neutral position of the clearance in the rotational direction. The rolling element is pressed against the narrow part at the end, but regarding the rotational movement from the cage,
The steering wheel operating force is transmitted to the pinion shaft while the rolling elements slide on the cylindrical surface and are disconnected from the drive system, and the manual steering force does not become excessive.

Furthermore, when recovering from a curve, when the steering wheel is returned from the wheel side, the driver applies only enough torque to lightly slide the steering wheel with his hand, so the torque is less than the set torque.
The clutch in the drive system does not operate and must be operated manually.

Therefore, by appropriately setting the spring force of the torque setting elastic member, it is possible to automatically switch to manual operation when the torque is below the set torque, and power steering when the torque exceeds the set torque, and to prevent abnormalities from occurring in the drive system including the motor etc. Even when the vehicle is moving, the manual steering force does not become excessive, and the steering wheel is returned smoothly without giving the driver a sense of discomfort when recovering from a curve.

〔Example〕

Embodiments of the present invention will be described below with reference to the accompanying drawings.

1 and 2 show a first embodiment of a clutch device according to the present invention.

As shown in the figure, a clutch inner ring 12 is incorporated inside the clutch outer ring 11, and a shaft 1 provided on the clutch inner ring 12
3 is rotatably supported by the clutch outer ring 11 via a bearing 14.

Further, a cylindrical retainer 15 is installed between the clutch outer ring 11 and the clutch inner ring 12, and a shaft 16 provided at the closed end of the retainer 15 is rotatably supported by the clutch outer ring 11 via a bearing 17. has been done.

A small diameter shaft portion 18 is formed on the end surface of the clutch outer ring 11 facing the closed end of the retainer 15.
is inserted into a recess 19 provided at the closed end of the retainer 15, and is rotatably supported via a bearing 20.

A cylindrical surface 21 is provided on the inner diameter surface of the clutch outer ring 11. On the other hand, the outer diameter surface of the clutch inner ring 12 is formed into a polygonal shape, and each plane thereof is a cam surface 22.
A cubic space 23 is formed between the cylindrical surface 21 and the cylindrical surface 21, which becomes gradually narrower toward both ends in the circumferential direction.

The cage 15 is provided with a pocket 24 corresponding to the cubic space 23, and two rolling elements 2 are placed in the pocket 24.
5.25' is incorporated.

Moreover, each rolling element 25 is provided between the two rolling elements 25 and 25'.
．． A spring 27 is incorporated which presses the pockets 25' in opposite directions to the wall surfaces 26 facing each other in the circumferential direction of the pocket 24.

The retainer 15 and the clutch inner ring 12 are engaged with each other via a pin 28. That is, as shown in FIG. 3, a pin 28 is provided on the outer diameter surface of the clutch inner ring 12, and the pin 28
is inserted into the fitting hole 29 formed in the retainer 15. The fitting hole 29 is long in the circumferential direction of the retainer 15, and a rotational clearance A is formed between the fitting hole 29 and the pin 28.

In order to hold the pin 28 at the neutral position of the rotational clearance A, torque setting elastic members 30 made of springs are installed on both sides of the pin 28. In the state where the pin 28 is held at the neutral position with the rotational direction clearance A, the rolling element 25
．． 25' does not engage either of the narrow portions at either end of the wedge-shaped space 23.

Here, the spring force of the torque setting elastic member 30 is
6, the torque setting elastic member 30 is bent until the rotational direction clearance A becomes zero, and the retainer 15 and the clutch inner ring 12 are determined to engage with each other. There is.

The clutch shown in the first embodiment has the above structure, and when this clutch device is used in an electric power steering device, a handle shaft 41 with a handle 40 is connected to the input shaft 16 as shown in FIG. Then, a shaft 44 of a pinion 43 that meshes with the rack 42 is connected to the output shaft 13.

Further, a sensor 45 is provided to detect twisting of the handle shaft 41, and this sensor 45 transmits the rotation of the motor 47 driven through the control device 46 to the clutch outer ring 11 via the torque transmission mechanism 48 of the gear electric mechanism. do. For this reason, a torque transmission member such as a gear is attached to the clutch outer ring 11.

In the assembled state as described above, when the handle 40 is rotated and a rotational force is applied to the retainer 15 of the input shaft 16 in the left direction in FIG. When the torque is less than that, the torque setting elastic member 30 has little deflection and the retainer 15 does not rotate much relative to the clutch inner ring 12, so the rolling elements 25 and 25' do not get caught in the narrow part of the wedge-shaped space 23. , the clutch does not operate.

Therefore, when the steering wheel operating force is small, no rotational force is transmitted from the clutch outer ring 11 to the clutch inner ring 12, and the steering wheel is operated manually.

The handle operation force increases, and the torque setting elastic member 30
When the set torque is exceeded, as shown in FIG. 4, the retainer 15 bends the torque setting elastic member 30 and rotates relative to the clutch inner ring 12 until the rotational direction clearance A disappears, and the pin is released from the retainer 15. 28, the operating force is transmitted to the wheels via the clutch inner ring 12, pinion shaft 44, pinion 43, and rack 42.

At the same time, the retainer 15 rotates leftward relative to the clutch inner ring 12, and of the pair of rolling elements 25 and 25' accommodated in the pocket 24, the left rolling element 25 is wedged by the elasticity of the spring 27. It is made to fit into the narrow part at the end of the space 23.

On the other hand, when the operating force is transmitted to the wheel, torque is generated on the handle shaft 41 due to resistance from the wheel, and this torque is detected by the sensor 45 provided on the handle shaft 41, and the control bag W46
The motor 47 is driven through. The rotation of the motor 47 is transmitted to the clutch outer ring 11. At this time, since the clutch is already in operation, the rotation of the motor 47 is
The power is transmitted from the clutch outer ring 11 to the clutch inner ring 12 via the rolling elements 25, and then to the wheels via the shaft 13, pinion shaft 44, pinion 43, and rack 42 of the clutch inner ring 12.

In this way, when the steering force exceeds the set torque, the system switches to power steering, and the wheels can be steered with a very small steering force.

In the unlikely event that an abnormality occurs in the drive system including the control device 46 and the motor 47 and these do not operate, the holder 15 connected to the handle shaft 41 will be rotated when the handle 40 is operated. The cage 15 is rotated relative to the clutch inner ring 12 in the left direction, and the rolling elements 25 are pressed against the narrow part of the wedge-shaped space 23 (see FIG. 4).
5, the clutch does not operate, and the rolling elements 25 slide on the cylindrical surface 21 of the clutch outer ring 11.

Therefore, from the retainer 15 to the pin 28, the clutch inner ring 1
2. Manual operating force is transmitted to the wheels via the pinion shaft 44, pinion 43, and rack 42, and is disconnected from the drive system, so the manual steering force does not become excessive.

Furthermore, the operation when the handle is returned from the wheel side when the drive system does not operate will be explained.

When recovering from a curve, force is transmitted from the wheels to the rack 42, pinion 43, pinion shaft 44, and clutch inner ring 12. In response to this steering wheel return force, the driver applies only enough torque to lightly slide the steering wheel with his hand.
This is less than or equal to the set torque of the torque setting elastic member 30. In this case, the retainer 15 does not rotate much relative to the clutch inner ring 12, so the rolling elements 25 accommodated in the pockets 24 of the retainer 15 are not pressed into the narrow part of the tree-shaped space 23. Therefore, the clutch does not operate, and the retainer 15 and the handle 40 connected thereto are returned in a state where the clutch inner race 12 is disconnected from the clutch outer race 11 (unrotatable).

Therefore, when recovering from a curve, the steering wheel can be returned smoothly without causing any discomfort to the driver.

In the first embodiment, the spring 27 housed in the pocket 24 may be a coil spring,
Alternatively, the leaf spring 27 may be a leaf spring as shown in FIG. 1O and FIG. 1
An inclined piece part is provided at both ends of the pressing piece part a, and a second pressing piece part C for pressing the other rolling element 25' is formed at both ends of the inclined piece part.

As shown in FIGS. 12 and 13, the second pressing piece C
A bent piece part d that engages with both end surfaces of the other rolling element 25' is provided at the end of the other rolling element 25', and a bent piece part d that engages with both end surfaces of the other rolling element 25' is provided on each of the first pressing piece part a, the inclined piece part A, and the second pressing piece part C. By using a leaf spring 27' formed with a retainer (e) into which a part of the retainer 25' is fitted, the retainer 15 is moved against the clutch inner ring 12 until the pair of rolling elements 25 and 25' come into contact with each other. Since the clutch can be rotated relative to each other, the operating angle of the clutch can be made larger than that of the clutch using the leaf spring 27 shown in FIG. A rolling element 25 with a large outer diameter is used as the moving element 25.25'.
．． 25' can be used, so the capacity of the clutch can be increased.

6 and 7 show a second embodiment of the clutch device according to the present invention. In this second embodiment, axial holes are provided in the clutch inner ring 120 shaft 13 and the shaft 16 of the retainer 15. 31, a torque setting elastic member 30' made of a torsion bar is inserted into the hole 31, and the torque setting elastic member 30' is fixed to each shaft 13, 16 via a holder 32.

Also, there is a rotational clearance A between the pin 28 and the fitting hole 29.
is provided. The other configurations and operations are the same as in the first embodiment, and their explanations will be omitted.

FIG. 8 shows a third embodiment of the clutch device according to the present invention. In this embodiment, instead of the torque setting member 30' consisting of a torsion bar in the second embodiment, a torque setting member 30' consisting of a leaf spring is used. A setting member 30'' is used.

FIG. 9 shows a fourth embodiment of the clutch device according to the present invention. In this clutch, a concave cam surface 22' is provided on the inner diameter surface of the clutch outer ring 11,
A cylindrical surface 21' is formed on the outer diameter surface of the second embodiment, and the cam surface and the cylindrical surface are arranged in the opposite manner to those in the first embodiment.

Further, a pin 28' is provided on the inner diameter surface of the clutch outer ring 11,
The pin 28' is inserted into a fitting hole 29 formed in the retainer 15 with a clearance A in the rotational direction.

Further, a torque setting elastic member 30 made of a spring is installed between the pin 28' and the fitting hole 29 to hold the pin 28' at the neutral position of the rotational clearance A.

When the clutch device described above is used in the electric power steering device shown in FIG. 5, the clutch outer ring 11 is connected to the pinion shaft 44 so that the rotational force of the motor 47 is transmitted to the clutch inner ring 12.

〔Effect of the invention〕

Since the present invention has the above configuration, the following effects can be obtained.

(a) When the torque is below the set torque, the rotational force is transmitted from the retainer to the member with the cam surface of the clutch inner ring and the clutch outer ring, and when the torque exceeds the set torque, the rotational force is transmitted to the retainer and the member with the cylindrical surface. This enables a clutch device that mechanically switches two inputs without external control and transmits them to a member having a cam surface.

Therefore, when the clutch of the present invention is used in an electric power steering device, it has a simple configuration using the setting spring force of the torque setting elastic member, and when the steering wheel operating force is less than the set torque, manual operation is performed, and the set torque When the torque exceeds 100 kW, it is possible to automatically switch to power steering, making it extremely suitable for integration into a power steering device.

←) Transmission reliability is high because the retainer is connected to the member having the cam surface through a mechanical engagement structure.

(c) The structure is simple and compact.

(b) By forming a cylindrical surface on the inner diameter surface of the clutch outer ring and providing a cam surface on the outer diameter surface of the clutch inner ring, processing means by cutting can be adopted for forming the cylindrical surface,
On the other hand, since processing means such as forging can be used to form the cam surface, it is easy to manufacture the clutch outer ring and the clutch inner ring.

(e) By using a torsion bar as the torque setting elastic member, it is easier to assemble and to set the torque setting value than when a coil spring is used as the torque setting elastic member.

(f) By using a temporary spring having a slit into which a part of the rolling elements fits as a spring that presses the two rolling elements in opposite directions, the operating angle of the clutch can be increased, or the clutch capacity can be increased.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal sectional view of a clutch device according to a first embodiment of the present invention, FIG. 2 is a sectional view taken along the line ■-■ in FIG. 1, and FIG. 3 is an enlarged sectional view of the same. FIG. 4 is a sectional view showing the operating state of the same as above, FIG. 5 is a schematic diagram of the clutch device of the present invention used in an electric power steering device, and FIG.
The figure is a longitudinal sectional view showing a second embodiment of the clutch device of the present invention, FIG. 7 is a sectional view taken along the line ■-■ in FIG. 6, and FIG.
9 is a longitudinal cross-sectional view showing a third embodiment of the clutch device according to the present invention, FIG. 9 is a cross-sectional view showing a fourth embodiment of the clutch device according to the present invention, and FIG. 1O is a pocket A plan view showing an example of a spring housed in the 11th
The figure is a sectional view taken along the line XI-XI in FIG. 10, FIG. 12 is a plan view showing another embodiment of the same spring, and FIG. 13 is a sectional view taken along the line xm-xm in FIG. 12. FIG. 14 is a schematic diagram showing a conventional electric power steering device. 11...Clutch outer ring, 12...
Clutch inner ring, 15...retainer, 21.21'...cylindrical surface, 22.22'...cam surface, 23...tree-shaped space, 24...Pocket, 25.25'...Rolling element, 27...
... Spring, 28 ... Pin
29...Fitting hole, 30.30', 30"...
...torque setting elastic member, A...rotational direction clearance, a...first pressing piece part, b... inclined piece part, C......th Pressing piece part 2, e...Slit. Patent Applicant: NCN Toyo Bearing Co., Ltd. Agent: Kama 1) Text 2 Figure 4 Figure 6 Figure 7 Negative 580

Claims (4)

[Claims] (1) A cylindrical surface is formed on one side of the inner diameter surface of the clutch outer ring and the outer diameter surface of the clutch inner ring assembled inside the outer ring, and an inclined cam surface is provided on the other, and the clutch inner ring is assembled between the clutch outer ring and the clutch inner ring. A pocket is provided in the cylindrical retainer at a position corresponding to the wedge-shaped space formed by the cylindrical surface and the inclined cam surface, and two rolling elements are placed in this pocket, and the rolling elements are pressed in opposite directions. The retainer is engaged with the member of the clutch outer ring and clutch inner ring on the side having the inclined cam surface with a clearance in the rotational direction, and the retainer is engaged with the member of the clutch outer ring and the clutch inner ring with a clearance in the rotational direction. A torque setting elastic member that adjusts the direction gap to a neutral position and elastically deforms until the rotational direction gap disappears when the set torque is exceeded is provided between the two engaging members, and further, in the neutral position, a pocket of the retainer is provided. 1. A clutch device characterized in that the rolling elements housed within the clutch device do not engage with either of the narrow portions at either end of the wedge-shaped space. (2) A cylindrical surface is formed on the inner diameter surface of the clutch outer ring, an inclined cam surface is provided on the outer diameter surface of the clutch inner ring, and the clutch inner ring is engaged with the retainer with a rotational clearance, and the clutch inner race and the retainer are 2. The clutch device according to claim 1, wherein the clutch devices are connected by a torque setting elastic member. (3) The clutch device according to claim 1 or 2, wherein the torque setting elastic member is formed from a torsion bar. (4) The spring consists of a leaf spring, a slit is formed in the length direction of the leaf spring into which a part of the rolling element fits, and the leaf spring is bent to press one of the pair of rolling elements. 1
2. The clutch device according to claim 1, further comprising: a pressing piece portion; an inclined piece portion at both ends of the pressing piece portion; and a second pressing piece portion for pressing the other rolling element at both ends of the inclined piece portion.