JPH078919Y2 - Drive pin for electromagnetic clutch - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] <Industrial Application Field> The present invention relates to a drive pin of an electromagnetic clutch suitable for intermittent driving force of an actuator for an automatic constant-speed traveling device of an automobile.

<Prior Art> For example, as disclosed in Japanese Utility Model Laid-Open No. 63-115930, a driving force is intermittently connected between a drive motor and an output shaft of an electric actuator of an automatic constant-speed traveling device for an automobile. It is customary to provide an electromagnetic clutch for In this electromagnetic clutch, when the excitation unit is excited, the armature plate is attracted to the clutch rotor on the drive source side,
A driving force is transmitted to a driven body from a clutch plate engaged with the armature plate such that relative displacement in the circumferential direction is impossible. As the engaging means between the armature plate and the clutch plate, a drive pin that engages with a radial groove formed in the clutch plate may be caulked and fixed to the armature plate.

This drive pin consists of a large diameter part that engages with the radial groove and a small diameter part that is caulked and fixed to the armature plate.However, because the impact force is directly applied when the clutch is engaged, stress is applied to the different diameter part. Tend to concentrate.

<Problems to be solved by the invention> On the other hand, when the drive pin is formed by forging, a plastic flow of the structure may occur in the different diameter portion, and as a result, the shear strength of the same portion decreases and breakage occurs. There was a risk of waking up.

The present invention has been devised to improve such inconvenience, and its main purpose is to provide a drive pin for an electromagnetic clutch improved so as not to cause processing defects during forging. It is in.

[Structure of the Invention] <Means for Solving the Problems> According to the present invention, such an object is formed on either the output side member or the armature plate in the electromagnetic clutch for an automatic constant speed traveling device. A drive pin, which is engaged with the radial groove and is caulked and fixed to the other to transmit torque, is formed into a small diameter portion and a large diameter portion by forging, and a hole is formed in the axial end surface of the large diameter portion. It is achieved by applying processing.

<Operation> As described above, by forming a hole in the axial end surface of the portion that becomes the large diameter portion of the drive pin during the forging process of the drive pin, it is possible to prevent the plastic flow of the structure from occurring and to cause a processing defect. It is possible to reduce the possibility of This hole can also be used for positioning during automatic assembly.

<Embodiment> Hereinafter, the construction of the present invention will be described in detail with reference to specific embodiments shown in the accompanying drawings.

FIG. 1 is a partially cutaway side view showing an essential part of an electromagnetic clutch used in an actuator of a vehicle automatic constant-speed traveling device constructed according to the present invention. In FIG. 1, a clutch rotor 4 in which a worm wheel 2 and an excitation unit 3 are integrally formed is coaxially and rotatably fitted to a fixed shaft 1 provided upright in a casing (not shown). There is.

A worm wheel 2 formed on the outer periphery of the clutch rotor 4 meshes with a worm gear (not shown) connected to a motor, and the clutch rotor 4 is rotated by rotationally driving the motor.

The excitation unit 3 is composed of a yoke 6 having an annular recess 5 whose upper part is open in the figure, and a coil bobbin 7 received in the annular recess 5. And coil bobbin 7
Is relatively tightly fitted to the inner peripheral surface of the annular recess 5 on the radially inner side, and by the retaining ring 8 made of a ferromagnetic material press-fitted and fixed to the open end side of the inner peripheral surface, the axial direction Has been positioned.

Above the clutch rotor 4, a disc-shaped armature plate 9 is pivotally attached to the fixed shaft 1 so as to face the clutch rotor 4, that is, the upper end surface 6a of the yoke 6, and is displaceable in the axial direction. It is worn. A disc-shaped clutch plate is provided above the armature plate 9.
Numeral 10 is pivotally attached to the fixed shaft 1 so as to be rotatable and non-displaceable in the axial direction. In addition, on the upper surface of the clutch plate 10,
The pinion gear 11 is fixed, and a sector gear (not shown) meshes with the sector gear to drive the throttle lever.

The armature plate 9 and the clutch plate 10 are connected to each other via, for example, three leaf springs 12. One end of each of these leaf springs 12 is connected to the clutch plate 10 with a rivet 13, and the other end thereof is connected to the armature plate 9 via a drive pin 14. As a result, the armature plate 9 is elastically supported in the axial direction between the clutch rotor 4 and the clutch plate 10, and is normally kept out of contact with the yoke 6.

The clutch plate 10 has, for example, three slots 15 that are open outward in the radial direction on the outer peripheral edge thereof at equal intervals. And drive pin 14 is this slot 15
Is adapted to engage with.

In the electromagnetic clutch thus configured, when the exciting unit 3 is selectively excited, the armature plate 9 is attracted to the yoke 6 against the elastic force of the leaf spring 12.
When the clutch rotor 4 is rotated by the driving force of the motor as described above, the pin 16 provided on the outer peripheral side of the yoke end surface 6a and the gear portion 17 provided on the outer peripheral portion of the armature plate 9 are engaged, Yoke 6 and clutch plate 10
Between armature plate 9 and drive pin
Torque is transmitted via 14. When the exciting unit 3 is de-excited, the armature plate 9
Is elastically pulled back to the clutch plate 10 side by the elastic force of the leaf spring 12 and separated from the yoke 6, and the engagement state between the pin 16 and the gear portion 17 is released.
Torque is not transmitted between the clutch plate 10 and the clutch plate 10.

By the way, the armature plate 9 and the clutch plate
As shown in FIG. 2, a drive pin 14 for preventing relative displacement in the circumferential direction with respect to 10 is inserted through a small diameter portion 14a into a through hole 9a provided in the armature plate 9, and a protruding end portion thereof is formed. It is connected to the armature plate 9 by caulking.

On the other hand, when the drive pin 14 is formed by forging, the plastic flow of the metal structure is disturbed in the stepped parts of different diameters of the small diameter part 14a and the large diameter part 14b, so that the shear strength of the same part is reduced. Processing defects may occur. This is drive pin 14
Is not preferable because it may cause breakage. Therefore, in the present invention, an appropriate hole 14c is forged in the axial end surface of the portion to be the large diameter portion 14b during or before the forging of the small diameter portion 14a and the large diameter portion 14b. There is. By this hole processing, the flow of the metal structure at the boundary portion between the small diameter portion 14 and the large diameter portion 14b is made smooth, and the possibility of causing processing defects in the same portion can be made extremely small.

[Advantage of the Invention] As described above, according to the present invention, since the reduction of the shear strength due to the non-uniformity of the plastic flow of the metal structure during the forging of the drive pin is prevented, the reliability of the strength is improved. There is a great effect in raising it. Moreover, since this processed hole can be used for positioning during automatic assembly, it is also effective in improving productivity.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a side view showing an essential part of an electromagnetic clutch according to the present invention with a part thereof broken away, and FIG. 2 is an enlarged sectional view of the essential part. It 1 ... Fixed shaft, 2 ... Worm wheel, 3 ... Excitation unit, 4 ... Clutch rotor, 5 ... Annular recess, 6 ... Yoke,
6a ... end face, 7 ... coil bobbin, 8 ... retaining ring, 9
... Armature plate, 9a ... Through hole, 10 ... Clutch plate, 11 ... Pinion gear, 12 ... Leaf spring, 13 ... Rivet, 14 ... Drive pin, 14a ... Small diameter part, 14b ... Large diameter part, 14
c ... hole, 15 ... slot, 16 ... pin, 17 ... gear

 ─────────────────────────────────────────────────── ─── Continuation of the front page (56) Bibliography Sho 60-16024 (JP, U) Rikai 61-194830 (JP, U) Rikai Hei 2-101130 (JP, U)

Claims (1)

[Scope of utility model registration request] Claim: What is claimed is: 1. An electromagnetic clutch for an automatic constant speed traveling device, wherein an output side member and an armature plate are engaged with a radial groove formed in either one of the output side member and the armature plate to transmit torque by being caulked and fixed to the other. A drive pin for an electromagnetic clutch, comprising a small-diameter portion and a large-diameter portion, being forged, and having a hole formed in the axial end surface of the large-diameter portion.