JP4518315B2 - Clutch unit - Google Patents

Description

  The present invention relates to a clutch unit that is incorporated in, for example, an automobile seat lifter section and performs transmission / cutoff of torque between an input side member and an output side member.

  In general, in a clutch unit using an engagement element such as a roller or a ball, a clutch portion is disposed between an input side member and an output side member. This clutch portion is composed of the input side member and the output side member described above. It is configured to control transmission / cutoff of input torque by engaging / disengaging rollers, balls, and other engaging elements in a wedge clearance formed therebetween.

  FIG. 16 is an enlarged view showing the clutch portion of the clutch unit. The clutch portion includes an outer ring 1 that is an input side member, an inner ring 2 that is an output side member, a roller 3 that is an engagement element, and a pocket 4. The main part is composed of the retainer 5 that holds the press-fitted roller 3. A cam surface 1 a is formed on the inner peripheral surface of the outer ring 1, and a wedge clearance 6 is formed between the cam surface 1 a of the outer ring 1 and the outer peripheral surface 2 a of the inner ring 2. As shown in FIGS. 18 to 20, the cage 5 has a plurality of pockets 4 formed at equal intervals in the circumferential direction, and a roller 3 is press-fitted into each pocket 4.

In this clutch portion, when the roller 3 is engaged with the wedge clearance 6 between the outer ring 1 and the inner ring 2, the input torque is transmitted from the outer ring 1 to the inner ring 2 via the roller 3, while the roller 3 is detached from the wedge clearance 6. Then, the outer ring 1 is idled with respect to the inner ring 2, and the input torque from the outer ring 1 is cut off without being transmitted to the inner ring 2 (see, for example, Patent Document 1).
JP 2003-166555 A

  By the way, in the clutch part of the clutch unit disclosed in Patent Document 1 described above, the cam surface 1a of the outer ring 1 and the outer peripheral surface 2a of the inner ring 2 in relation to the outer ring 1, the roller 3 and the inner ring 2 as shown in FIG. In between, the roller 3 is inserted into the pocket 4 of the cage 5 with a predetermined radial clearance m. If a radial clearance m exists between the roller 3 and the cam surface 1a of the outer ring 1, a circumferential play a of the outer ring 1 is obtained as shown in FIG.

  When it is desired to regulate the circumferential play a of the outer ring 1 below a certain value, the inner diameter dimension of the cam surface 1a of the outer ring 1 and the outer diameter dimension of the inner ring 2 are measured, and the roller 3 having a diameter d that matches the space. Will be inserted. This is generally referred to as selective fitting, but in this selective fitting, several types of rollers having different diameters are generated.

  On the other hand, when the circumferential width w of the pocket 4 is larger than the diameter d of the roller 3, a gap is generated between the pocket 4 and the roller 3, and the roller 3 is loose in the pocket 4. As a result, the circumferential play a of the outer ring 1 is further increased, and it becomes difficult to regulate the circumferential play a of the outer ring 1 to a predetermined value. Further, as described above, if there is a clearance between the pocket 4 and the roller 3, the roller 3 will strike the outer ring 1 or the inner ring 2 due to vibration and generate vibration noise.

  For this reason, when it is desired to regulate the circumferential play a of the outer ring 1 to a certain value or less, it is desirable to make the circumferential width w of the pocket 4 of the cage 5 smaller than the diameter d of the roller 3. However, in that case, when the roller 3 is inserted into the pocket 4 of the cage 5, the roller 3 is press-fitted into the pocket 4, so that the roller 3 is in a strong pressure state in the pocket 4, and the roller 3 has a diameter in the pocket 4. It becomes difficult to move easily in the direction. Then, the roller 3 may not engage with the wedge clearance 6 between the outer ring 1 and the inner ring 2, and there is a possibility that the input torque from the outer ring 1 cannot be transmitted to the inner ring 2.

  Therefore, the present invention has been proposed in view of the above-mentioned problems, and the object of the present invention is to ensure that the input torque from the outer ring is applied to the inner ring even when the roller is in a high pressure state in the pocket of the cage. It is to provide a clutch unit capable of transmitting.

As technical means for achieving the above-described object, the present invention provides an input side member to which torque is input, an output side member to which torque is output, and an input torque from the input side member to the output side member. A plurality of engaging elements, and a cage in which pockets for holding the engaging elements in a press-fitted state are formed at equal intervals in the circumferential direction, and the gap formed between the input side member and the output side member In the clutch unit that controls the transmission / cutoff of input torque from the input side member by engaging / disengaging the engagement element, the retainer reduces the frictional force with the engagement element held in a press-fit state in the pocket. The protrusion to be formed is formed on the circumferential surface of the pocket .

Since the retainer in the clutch unit according to the present invention is formed with a protrusion on the circumferentially opposed surface of the pocket to reduce the frictional force with the engagement member held in a press-fit state in the pocket, The frictional force of the press-fitted engagement element can be reduced. As a result, even when the engagement element is in a high pressure state in the cage pocket, the engagement element easily moves in the radial direction within the pocket, and the engagement element is surely provided in the wedge clearance between the input side member and the output side member. Therefore, the input torque from the input side member can be reliably transmitted to the output side member.

A plurality of the protrusions described above can be arranged in parallel on the circumferential surface of the pocket along the axial direction. The protrusion may be defined to have a protruding dimension in which the force acting on the engagement element from the input side member is equal to or greater than the force acting on the engagement element due to the frictional force with the cage.

With structure provided with projections, as described above, by simple means, the engaging element since is securely engageable with the wedge gap between the output-side member and the input side member, from the input-side member It is easy to reliably transmit the input torque to the output side member.

  The clutch unit according to the present invention is used by being incorporated in an automobile seat lifter. In this case, the input side member is coupled to the operation lever, and the output side member is connected to the rotating member of the automobile seat lifter portion. When this clutch unit is incorporated in an automobile seat lifter section, the operation lever in the seat lifter section is not swung, so that reliable lever operation is possible.

According to the present invention, the retainer is press-fitted into the pocket of the retainer by forming the protrusion on the circumferentially opposite surface of the pocket so as to reduce the frictional force with the engagement member held in the press-fit state in the pocket. The frictional force of the engaged member can be reduced. As a result, even when the engagement element is in a high pressure state in the cage pocket, the engagement element easily moves in the radial direction within the pocket, and the engagement element is surely provided in the wedge clearance between the input side member and the output side member. Thus, the input torque from the input side member can be reliably transmitted to the output side member, and a highly reliable and high quality clutch unit can be provided. In addition, when this clutch unit is incorporated in, for example, a seat lifter that adjusts a seat of an automobile, a reliable lever operation is possible and operability can be improved.

  1 to 3 show the overall configuration of a clutch unit according to an embodiment of the present invention. The clutch unit of this embodiment includes a first clutch portion 11 (see FIG. 2) provided on the input side and a second clutch portion 12 (see FIG. 3) as a reverse input blocking mechanism provided on the output side. It has.

  The first clutch portion 11 includes an outer ring 13 as an input side member, an inner ring 14 as an output side member, a plurality of rollers 15 as an engagement element, a cage 16 that holds the rollers 15, and two types of elasticity. Members 17 and 18. On the inner periphery of the outer ring 13, a plurality of cam surfaces 13a are formed at equal intervals in the circumferential direction. The inner ring 14 includes an outer peripheral surface 14 a that forms a wedge clearance 20 between the outer ring 13 and the cam surface 13 a of the outer ring 13. The retainer 16 has a plurality of pockets 19 for accommodating the rollers 15 as shown in FIGS. Each of the elastic members 17 and 18 is an end ring-shaped leaf spring formed by rolling a belt plate material, and one elastic member 17 is disposed on the outer diameter side of the other elastic member 18.

  The elastic member 17 located on the outer diameter side is disposed between the outer ring 13 and the outer ring 21 of the second clutch portion 12 that is a stationary side member, and elastic force is generated during rotation when input torque acts from the outer ring 13. When the accumulated torque is lost, the outer ring 13 returns to the neutral state by the elastic restoring force. The elastic member 18 positioned on the inner diameter side is disposed between the cage 16 and the outer ring 21, and elastic force is accumulated by rotation of the cage 16 when the input torque from the outer ring 13 is applied. When there is no more, the cage 16 returns to the neutral state due to the elastic restoring force.

  On the other hand, the second clutch portion 12 includes an inner peripheral surface 21 a of the outer ring 21, a plurality of cam surfaces 22 a provided on the outer diameter of the output shaft 22 at equal intervals in the circumferential direction, and an inner peripheral surface 21 a of the outer ring 21 and an output. A pair of rollers 24 as an engagement member interposed between the cam surfaces 22 a of the shaft 22, an elastic member interposed between the pair of rollers 24, for example, a plate spring 25 having an N-shaped cross section, a roller 24, and a plate spring 25. The inner pocket 14 of the first clutch portion that functions as a cage in which the pockets 23 to be accommodated are formed at equal intervals in the circumferential direction is configured as a main portion.

  The output shaft 22 has a plurality of pin holes 22b formed at predetermined circumferential intervals, and the pins 14b of the inner ring 14 are inserted into the pin holes 22b. A wedge clearance 26 is formed between the inner peripheral surface 21 a of the outer ring 21 and the cam surface 22 a of the output shaft 22. Further, the outer ring 21 is formed with a locking portion (not shown) that engages with the elastic members 17 and 18 of the first clutch portion 11.

  In the first clutch portion 11 described above, when input torque acts on the outer ring 13, the roller 15 engages with the wedge clearance 20, and torque is transmitted to the inner ring 14 via the roller 15, so that the inner ring 14 rotates. At this time, an elastic force is accumulated in both elastic members 17 and 18 as the outer ring 13 and the cage 16 are rotated. When the input torque disappears, the outer ring 13 and the retainer 16 are returned to the neutral state by the elastic force of the elastic members 17 and 18, while the inner ring 14 maintains the given rotation position. Therefore, the rotation amount of the outer ring 13 is repeatedly accumulated in the inner ring 14 due to repeated rotation.

  In the second clutch portion 12, when reverse input torque is input to the output shaft 22, the roller 24 engages with the wedge clearance 26 and the output shaft 22 is locked to the outer ring 21. Accordingly, the reverse input torque from the output shaft 22 is locked by the second clutch portion 12 and the return of the reverse input torque to the first clutch portion 11 is interrupted.

  On the other hand, the input torque from the outer ring 13 is input to the inner ring 14 via the first clutch portion 11, and the inner ring 14 engages with the roller 24 and presses against the elastic force of the leaf spring 25, so that the roller 24 is removed from the wedge clearance 26, the locked state of the output shaft 22 is released, and the output shaft 22 can rotate. When the inner ring 14 is further rotated, the pin 14b of the inner ring 14 is engaged with the pin hole 22b of the output shaft 22, whereby the input torque from the inner ring 14 is transmitted to the output shaft 22 through the pin 14b and the pin hole 22b. The output shaft 22 rotates. When the input torque from the inner ring 14 is lost, the neutral state is restored by the elastic restoring force of the leaf spring 25.

  In the clutch unit of this embodiment, as shown in FIGS. 5 and 6, a protrusion 31 is provided on the circumferentially facing surface of the pocket 19 of the cage 16 in the first clutch portion 11. The protrusions 31 are arranged in parallel along the axial direction on the circumferentially opposed surface of the pocket 19 of the cage 16. In this embodiment, two protrusions 31 are formed, but the number of protrusions 31 can be arbitrarily set in addition to the two protrusions.

  In this clutch unit, by providing the protrusion 31 on the circumferentially facing surface of the pocket 19 of the cage 16, the frictional force of the roller 15 press-fitted into the pocket 19 of the cage 16 can be reduced. As a result, even if the roller 15 is in a strong pressure state in the pocket 19 of the retainer 16, the roller 15 easily moves in the radial direction in the pocket 19, and the roller 15 has a wedge clearance 20 between the outer ring 13 and the inner ring 14. Therefore, the input torque from the outer ring 13 can be reliably transmitted to the inner ring 14.

Here, the engagement of the roller 15 in the wedge clearance 20 between the outer ring 13 and the inner ring 14 will be described with reference to FIG. Normally, the cage 16 tries to stay at a predetermined load P by the elastic member 18. When the outer ring 13 rotates counterclockwise, the retainer 16 tries to stay, so that only the outer ring 13 rotates, and the force P ₂ that the roller 15 contacts with the cam surface 13a of the outer ring 13 and receives from the cam surface 13a. As a result, the roller 15 is pushed down to come into contact with the inner ring 14, the roller 15 is engaged, and torque is transmitted to the inner ring 14.

P is a force for the retainer 16 to stay by the elastic member 18, P _{1 is} a force acting in the circumferential direction (left direction in the figure) from the outer ring 13 to the roller 15, and a radially inner side (in the figure from the outer ring 13 to the roller 15). If the force acting in the downward direction is P ₂ , and the force (frictional force) that the roller 15 press-fitted into the retainer 16 moves radially outward is Q ₂ , P ₂ <Q ₂ In this case, even if the outer ring 13 rotates and the cam surface 13a comes into contact with the roller 15, the roller 15 is not pushed down by the force from the cam surface 13a. That is, since the outer ring 13, the cage 16, and the roller 15 rotate in synchronization, the input torque from the outer ring 13 cannot be transmitted to the inner ring 14 side.

Therefore, the dimensional relationship between the circumferential width W of the pocket 19 of the cage 16 and the outer diameter D of the roller 15 is adjusted so that the outer ring 13 does not idle. As the adjusting means, as described above, the protrusion 31 is provided on the circumferentially opposed surface of the pocket 19 of the cage 16, and the radially inward force P ₂ acting on the roller 15 from the outer ring 13 is caused by friction with the cage 16. The protrusion dimension n of the protrusion 31 is set so that the radially outward force Q ₂ acting on the roller 15 by the force is greater than P ₂ ≧ Q ₂ . In this way, the roller 15 can be more reliably engaged by the wedge clearance 20 between the outer ring 13 and the inner ring 14, so that the input torque from the outer ring 13 can be more reliably transmitted to the inner ring 14.

  8 and 9 show the relationship between the roller tightening allowance and the roller friction force when the roller 15 is press-fitted into the pocket 19, and FIG. 8 shows a conventional cage 5 (FIG. 8) in which no protrusion is formed in the pocket. FIG. 9 shows the cage 16 (see FIGS. 4 to 6) of the present invention in which the protrusions 31 are formed in the pockets 19 respectively. As apparent from a comparison between FIG. 8 and FIG. 9, the roller frictional force can be reduced with respect to the roller tightening margin when the protrusions 31 are provided in the pocket 19.

FIG. 10 shows the relationship between the roller tightening allowance and the roller frictional force as an actually measured value. In FIG. 10, the roller 15 is an area where the outer ring 13 and the inner ring 14 are reliably engaged in the OK range. the cash is 0.035mm or less, roller frictional force (moving load of the roller) is less than 420 g, this value becomes the load P _2. The protrusion dimension n of the protrusion 31 depends on the strength of the resin material constituting the cage 16 and cannot be determined uniformly, but can be, for example, about 0.05 mm.

  In the embodiment described above, a structure in which the protrusion 31 is provided on the circumferentially opposed surface of the pocket 19 of the cage 16 as a friction reducing means for reducing the frictional force with the roller 15 held in the pocket 19 in a press-fitted state. However, the present invention is not limited to this, and other friction reducing means can be employed.

As the friction reducing means, it can be realized by adding an additive to the material constituting the cage. As the additive, the radially inward force P ₂ acting on the roller 15 from the outer ring 13 is equal to or greater than the radially outward force Q ₂ acting on the roller 15 due to the frictional force with the cage 16, that is, P What should be selected is ₂ ≧ Q ₂ . The cage 16 ′ shown in FIGS. 11 to 13 is the same in form as the conventional cage 5 (see FIGS. 18 to 20), but the material is different.

  That is, the cage 16 'of this embodiment is made of a Teflon (registered trademark) or two-component material that generally has a property of reducing the friction coefficient in a material in which 25% glass fiber is blended with polyamide (PA) resin, for example, nylon 66. Molybdenum sulfide is used as an additive. Here, Teflon means PTFE (polytetrafluoroethylene) which is a tetrafluoride resin.

Thus, by changing the material of the cage 16 ', the friction coefficient of the cage 16' is lowered. In other words, the radially outward force Q ₂ acting on the roller 15 decreases, so that the radially inward force P ₂ acting on the roller 15 from the outer ring 13 is caused by the frictional force with the cage 16 ′. It is easy to establish a relationship of P ₂ ≧ Q ₂ or more, that is, a radially outward force Q ₂ acting on.

  As a result, even if the roller 15 is in a strong pressure state in the pocket 19 of the cage 16 ′, the roller 15 is easily moved in the radial direction in the pocket 19, and the roller 15 is wedge-clearance between the outer ring 13 and the inner ring 14. Thus, the input torque from the outer ring 13 can be reliably transmitted to the inner ring 14.

  The clutch unit having the structure described in detail above is used by being incorporated in, for example, an automobile seat lifter portion. FIG. 14 shows a seat 40 installed in a passenger compartment of an automobile. The seat 40 includes a seat 40a and a backrest 40b, and includes a seat lifter 41 that adjusts the height H of the seat 40a. The height H of the seating seat 40a is adjusted by the operation lever 41a of the seat lifter 41.

FIG. 15A conceptually shows one structural example of the sheet lifter unit 41. Seat slide adjuster 41b of the slide moving member 41b ₁ to the link member 41c, one end of 41d are respectively rotatably hinged. The other ends of the link members 41c and 41d are pivotally attached to the seating seat 40a. The other end of the link member 41c is pivotally attached to the sector gear 41f via the link member 41e. Sector gear 41f is pivotally rotatably sitting seat 40a, a swingable fulcrum 41f ₁ around. The other end of the link member 41d is pivotally attached to the seating seat 40a. The clutch unit X of the embodiment is fixed to an appropriate part of the seating seat 40a, and an operation lever 41a made of resin, for example, is coupled to the outer ring 13 that is an input side member, and the sector gear 41f is connected to the output shaft 22 that is an output side member. The pinion gear 41g which meshes with is connected.

  For example, in FIG. 15B, when the operation lever 41a is swung counterclockwise (upward), the input torque in that direction is transmitted to the pinion gear 41g via the clutch unit X, and the pinion gear 41g is counterclockwise. Rotate. Then, the sector gear 41f that meshes with the pinion gear 41g swings in the clockwise direction, and pulls the other end of the link member 41c through the link member 41e. As a result, both the link member 41c and the link member 41d stand up, and the seating surface of the seating seat 40a is raised.

  Thus, after adjusting the height H of the seating seat 40a, when the operation lever 41a is opened, the operation lever 41a is rotated clockwise by the elastic force of the elastic members 17 and 18 to return to the original position (neutral state). Return to). When the operation lever 41a is swung clockwise (downward), the seating surface of the seating seat 40a is lowered by the reverse operation. When the operation lever 41a is released after the height adjustment, the operation lever 41a rotates counterclockwise and returns to the original position (neutral state).

It is sectional drawing which shows the clutch unit in embodiment of this invention. It is sectional drawing which follows the II line | wire of FIG. It is sectional drawing which follows the II-II line of FIG. (A) is sectional drawing which follows the III-III line of (b), (b) is sectional drawing which shows the holder | retainer of FIG. 1 and FIG. 2, (c) is a right view of (b). It is a perspective view which shows the holder | retainer of FIG. It is a partial expansion perspective view which shows the pocket of FIG. FIG. 2 is a partially enlarged cross-sectional view showing an outer ring, an inner ring, a cage, and a roller in FIG. It is a characteristic view which shows the relationship between the roller interference and the roller frictional force in the conventional product. It is a characteristic view which shows the relationship between the roller interference and roller frictional force in this invention product. It is a characteristic view which shows the relationship (actual value) of the roller interference and roller frictional force in this invention. It is a holder | retainer in other embodiment of this invention, (a) is sectional drawing which follows the IV-IV line of (b), (b) is sectional drawing, (c) is a right view of (b). It is a perspective view which shows the holder | retainer of FIG. It is a partial expansion perspective view which shows the pocket of FIG. It is a conceptual diagram which shows the seat seat of a motor vehicle. (A) is a conceptual diagram which shows one structural example of a sheet lifter part, (b) is the principal part enlarged view. It is a partial expanded sectional view which shows an outer ring | wheel, an inner ring | wheel, a holder | retainer, and a roller with the conventional clutch unit. It is sectional drawing for demonstrating the circumferential play of an outer ring | wheel with the conventional clutch unit. (A) is sectional drawing which follows the VV line of (b), (b) is sectional drawing which shows the holder | retainer in the conventional clutch unit, (c) is a right view of (b). It is a perspective view which shows the holder | retainer in the conventional clutch unit. It is a partial expansion perspective view which shows the pocket of FIG.

Explanation of symbols

13 Input side member (outer ring)
14 Output side member (inner ring)
15 Engagement element (roller)
16 Cage 19 Pocket 31 Projection

Claims (5)

An input side member to which torque is input, an output side member to which torque is output, a plurality of engagement elements that transmit input torque from the input side member to the output side member, and a pocket that holds each engagement element in a press-fit state And a cage formed at equal intervals in the circumferential direction, and by engaging and disengaging the engagement element in a gap formed between the input side member and the output side member, input from the input side member In the clutch unit for controlling transmission / cutoff of torque, the retainer has a protrusion formed on a circumferentially opposed surface of the pocket for reducing a frictional force with an engagement member held in a press-fit state in the pocket. And clutch unit. 2. The clutch unit according to claim 1 , wherein a plurality of the protrusions are juxtaposed along the axial direction on a circumferentially opposed surface of a pocket of the cage. The protrusions clutch unit according to the force acting from the input-side member to the engaging elements to claim 1 or 2 as specified in the projecting dimension of the force than that acting on the engaging member by the frictional force between the cage. Clutch unit according to any one of claims 1 to 3 which is incorporated into the seat lifter section for an automobile. The clutch unit according to claim 4 , wherein the input side member is coupled to an operation lever, and the output side member is coupled to a rotating member of an automobile seat lifter portion.

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