JPH03229966A - Starter - Google Patents

Abstract

PURPOSE:To heighten durability and the stability of set torque by transmitting the rotational torque of an armature shaft to a gear side taper part from a shaft side taper part by frictional coupling, and further onto a pinion and a ring gear through gear speed reducing mechanism. CONSTITUTION:An armature shaft 1 protruding from an armature 15, a D.C. motor, is provided with a shaft side taper part 1a, and a taper bush 2 is fittingly secured thereto. An armature gear 3 is rotatably fitted at the armature shaft 1, and a gear side taper part 3a provided at one end of the armature gear 3 is brought into contact with the shaft side taper part 1a. The armature gear 3 is meshed with a clutch gear formed at the outer cylinder part of a clutch 10 through an idle gear 7. A magnet switch 13 is disposed coaxially with the clutch 10, and at the closed time of this magnet switch 10, the shaft of a plunger 21 is sucked to move a pinion 11 to the left through the shaft of the clutch 10 so as to mesh the pinion 11 with a ring gear 12.

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to a starter used for starting an internal combustion engine.

[Prior Art] Conventionally, there have been starters in which the weight of the pinion has been reduced by using resin, but such resin pinions are susceptible to impact, and the problem that the teeth of the resin pinion often break due to impact during meshing occurs. In order to improve this problem, Nippondenso Technical Report 49-096 (published September 15, 1986) proposed that the contact surface between the resin pinion and the tube (shaft) inserted into the shaft hole of the resin pinion be tapered. As such, the resin pinion and the tube are fitted in a tapered manner, and slippage is generated on the tapered surface at a constant torque of 1 to 100 mph to prevent damage to the teeth of the resin pinion. Furthermore, it is also disclosed that an adjusting nut is provided at one end of the tube and the sliding torque of the tapered surface is adjusted by turning the adjusting nut to the adjusting nut 1.

[Problems to be Solved by the Invention] However, it has been found that while the stator having the above-mentioned tapered fitting allows easy adjustment of the sliding torque, it has the following problems.

First, is it necessary for this tapered fitting part to constantly slip at a slippage of 1 to 100 mph or more?The coefficient of friction of a tapered fitting part fluctuates greatly due to the intrusion of dust, oil, moisture, etc. As a result, the slip torque changes significantly over time or due to factors such as changes in weather conditions. An increase in slipping torque causes tooth loss in the pinion, and a decrease in slipping torque makes it impossible to transmit the necessary torque.

Second, when the tapered surface wears, the friction coefficient of the tapered fitting portion decreases, and the sliding torque decreases.

The present invention has been made in view of the above problems, and an object to be solved is to provide a starter that is highly durable and stable in set torque, and can be made smaller and lighter.

[Means for Solving the Problems] A starter according to a first aspect of the invention includes an armature, an armature gear rotatably and axially movably fitted onto the shaft of the armature, and a shaft-side tapered surface. A shaft-side tapered portion disposed, a gear-side tapered portion disposed on the armature gear having a gear-side tapered surface frictionally coupled with the shaft-side tapered surface, and a lubricant loaded between the two tapered surfaces. an adjustment nut that is screwed onto the tip of the shaft and that pivots to push the armature gear to adjust the sliding torque between the two tapered surfaces; and an adjustment nut that transmits the fetal torque of the armature gear to a ring gear for starting the engine. It is characterized by comprising a gear reduction mechanism.

The starter of the second invention includes an armature, an armature gear rotatably and axially movably fitted to the shaft of the armature, and a shaft-side tapered portion having a shaft-side tapered surface and disposed on the shaft. , a gear-side tapered portion having a gear-side tapered surface that frictionally engages with the shaft-side tapered surface and disposed on the armature gear; An adjustment nut that adjusts the sliding torque between both tapered surfaces, a gear reduction mechanism that transmits the starting torque of the armature gear to a ring gear for starting the engine, and at least one of the axially movable tapered portions is provided with a predetermined attachment. It is characterized by comprising a biasing means that biases in the axial direction with a force to increase the sliding torque.

In a preferred aspect of the second invention, the shaft-side tapered portion is fitted to the shaft so as to be integrally rotatable and movable in the axial direction, and the biasing means is fitted to the shaft to move the shaft-side tapered portion in the axial direction. It consists of an elastic member that biases.

In a preferred embodiment of the second invention, the biasing means includes a disc spring that is fitted onto the shaft and biases the armature gear in the axial direction.

In a preferred embodiment of the second invention, a lubricant is loaded between both tapered surfaces.

[Operation and Effects of the Invention] In the starters of both inventions, the rotational torque of the shaft of the armature is transmitted from the shaft-side taper part to the gear-side taper part through frictional coupling, and further from the gear-side taper part to the gear reduction mechanism, pinion, and ring gear. It is transmitted by tooth alignment in this order. When the transmission torque between both tapered surfaces exceeds the preset slipping torque, slipping occurs between both tapered surfaces and the impact is alleviated.

In particular, in the starters of the first and second inventions, frictional coupling is achieved between the armature shaft and the gear reduction mechanism through tapered fitting, so both tapered parts can be made smaller, and the tapered surfaces are subject to wear and tear due to meshing impact. was found to be reduced.

In other words, by doing this, the transmission torque between both tapered surfaces can be reduced by the reduction ratio of the gear reduction mechanism compared to the conventional example in which a tapered part is provided at the pinion part.
Therefore, both tapered portions can be made smaller, and the inertial energy and impact can be reduced by the amount of the smaller size and lighter weight. Further, wear and tear on the tapered surface due to meshing impact is reduced.

That is, the meshing impact generated between the ring gear and the pinion is compressed by the reduction ratio of the gear reduction mechanism and applied to both tapered surfaces, and therefore the wear on both tapered surfaces due to the meshing impact is reduced by this compression.

Furthermore, in the first invention, the lubricant loaded in the tapered surface portion or
It is possible to prevent wear of both tapered surfaces, prevent a decrease in slip 1 to torque between both tapered surfaces caused by this wear, and prevent fluctuations in sliding torque over time.

Furthermore, in the second aspect of the present invention, since the tapered portion is provided with a biasing means that biases at least one of the tapered portions movable in the axial direction in the axial direction with a predetermined biasing force to increase the sliding torque, the tapered portion is not worn out. Even if the distance between the tapered surfaces changes due to the biasing means, the biasing means moves at least one of the tapered portions in the axial direction and keeps the frictional force between the tapered surfaces constant, thereby reducing the sliding torque due to wear. prevent a decline in

[Example] (First Example) An example of the starter of the present invention is shown in FIG. 1, and an enlarged sectional view of the main part is shown in FIG.

This starter is of a three-shaft type, and each of its parts, except for the pinion 11, is housed in a housing 9. The pinion 11 protrudes from the opening of the housing 9 so as to be able to mesh with the ring gear 12. The pinion 11 can be biased in the axial direction by the shifter 1 of the plunger 21 via the shaft 2o of the clutch 1o. A clutch gear is formed in the outer cylindrical portion of the clutch 1o, which is rotatably fitted onto the shaft 2° of the clutch 1o.The clutch gear meshes with an idle gear 7 pivotally supported by a pin 8. 7 meshes with armature gear 3.

On the other hand, an armature shaft 1 protruding from an armature 15, which is a DC motor, is provided with a shaft-side taper portion 1a, and a taper bushing 2 is fitted into the shaft-side taper portion 1a.

The taper bush 2 is made of a bearing material such as phosphor bronze, and a large number of small recesses 2a are provided on both sides of the tape bush 2 for storing grease.

An armature gear 3 is rotatably fitted onto the armature shaft 1. A gear-side taper portion 3a provided at one end of the armature gear 3 is in contact with the shaft-side taper portion 1a. An adjustment nut 6 is screwed onto one end of the armature shaft 1, and a thrust bearing 18 is interposed between the adjustment nut 6 and the armature gear 3. The adjusting nut 6 is connected to the armature gear 3 via a thrust bearing 18.
is pressed in the axial direction to frictionally connect both tapered surfaces 1a and 3a via taper push 2, and the sliding torque between both tapered surfaces 1a and 3a can be adjusted by turning the adjustment nut 6. An O-ring 4 is provided at the end of the shaft-side tapered portion 1a on the larger diameter side.
seals the grease and prevents foreign matter from entering the interior.

In addition, the armature gear 3 is connected to the and is supported by the housing 9.

A magnetic switch 13 is provided at one end of the shaft 31 of the plunger 30.
One contact is connected to the positive electrode of the battery 16, and the contact of the magnetic switch 13 is grounded via the armature 15.

A suction coil PC and a holding coil HC are wound around the shaft of the plunger 21, one end of the holding coil HC is grounded, one end of the suction coil PC is connected to a contact on the armature 15 side of the magnetic switch 13, Each narrow end of the holding coil HC and the suction coil PC is connected to the positive electrode of the battery 16 via a starter switch 17.

The operation of this starter will be explained below.

When the starter switch 17 is turned on, the attraction coil PC and the holding coil HC are energized to attract the shaft of the plunger 21, and the pinion 11 is pushed to the left in the figure and meshes with the ring gear 12. The pinion 11 is the ring gear 12
When engaged, the magnetic switch 13 closes and a current flows into the armature 15, causing the armature 15 to rotate at high speed. Rotate. When the engine starts, the clutch 10 idles to prevent the armature 15 from being driven in reverse.

What is important in the above configuration is that both tapered surfaces 1a and 3a
Adjustment is made so that the sliding torque between the pinion 11, the ring gear 12, the idle gear 7, and the armature gear 3 is set to be less than the damage torque of the armature gear 3,
As a result, when the armature 15 is restarted during inertia rotation, the above-mentioned gear parts can be protected from impact damage at the time of re-meshing.

The thrust bearing 18 prevents the adjusting nut 6 from rotating when the armature gear 3 slips, thereby preventing the set slip torque value from changing.

Taper bush 2 with grease reservoir 2a (see Figure 2)
This significantly improves the wear resistance of the armature shaft 1, both tapered surfaces 1a, 3a of the armature gear 3, and the chip bush 2, and prevents fluctuations in sliding torque due to progress of wear. The taper bush 2 may be made of phosphor bronze, and an oil-less bush, solid lubricant, or the like may be used.

Other sealing means such as an oil seal may be used instead of the O-ring 4. In addition, in FIG. 1, the tip of the armature shaft is caulked in the direction of diameter expansion to prevent the adjustment nut 6 from returning.

(Second example) Another embodiment of the starter of the present invention is shown in FIG.

This starter includes a tapered barrel (shaft side taper portion in the present invention) 500 that is movable in the axial direction, and a book spring (book spring) that urges the tapered barrel 500 in the axial direction with a predetermined urging force to increase the sliding torque. This starter has almost the same configuration as the starter of the first embodiment, except that it is provided with a biasing means >400 as defined in the invention.

That is, the armature shaft 1 has a disc spring 4.
00. Washer 200. A taper barrel 500 is fitted, and a taper bushing 1 of a predetermined thickness is provided on the shaft side taper surface 1a of the taper barrel 500.
The gear-side tapered surface 3a of the gear-side tapered portion 300 is frictionally coupled via the gear-side tapered portion 300. In addition, the gear side taper part 300 is constituted by the right side part of the armature gear 3 in the figure. Further, in contact with both end surfaces of the taper bush 1, an O-ring 2b is provided on the larger diameter side and an oil-impregnated felt 2C is provided on the smaller diameter side to seal this taper fitting area.

The inner peripheral surface of the tapered barrel 500 and the tapered barrel 50
The outer peripheral surface of the shaft 1 into which the barrel 500 is fitted is provided with grooves that are carved parallel to the axial direction and engage with each other, and this engagement causes the tapered barrel 500 to move along the shaft 1 in the axial direction. It is movable.

Further, one end surface of the disc spring 400 is supported by the armature 15, and the other end surface biases the taper barrel 500 in the left direction (in the direction of increasing friction) in the figure via the washer 200.

To explain the operation of the main parts of this starter, even if the tapered surfaces 1a and 3a and the taper bushing 24 are worn out due to the meshing impact, the disc spring 400
0 in the axial direction, and as a result, these tapered surfaces 1a
, 3a are always applied with a constant pressing force regardless of wear, thereby preventing a decrease in sliding torque.

According to this embodiment, the sliding torque is transferred to the disc spring 4.
Since the adjustment nut 6 can be specified as 00, the adjustment nut 6 can also be omitted.

As a modification of this embodiment, for example, a book spring may be interposed on the armature shaft 1 between the adjustment nut 6 and the armature gear 3, and the armature gear 3 may be biased in the direction of increasing friction by this disc spring. good. According to this modification, the tapered barrel 500 can be omitted, and the configuration can be simplified.

[Brief explanation of drawings]

FIG. 1 is a sectional view showing an embodiment of the starter of the present invention, and FIG. 2 is an enlarged sectional view of the main part thereof. FIG. 3 is a sectional view showing another embodiment of the present invention. 1... Armature shaft (shaft) 5 1a... Shaft side tapered surface 2... Taper bush (lubricant) 3a... Gear side tapered surface 3... Armature gear 6... Adjustment nut 7...・Idle gear (gear reduction mechanism) 15... Armature 18... Thrust bearing 100... Shaft side taper part 300... Gear side taper part 500... Taper barrel (shaft side taper part)

Claims (5)

[Claims] (1) An armature, an armature gear rotatably and axially movably fitted to the shaft of the armature, a shaft-side tapered portion having a shaft-side tapered surface and disposed on the shaft, and the shaft side a gear-side tapered part disposed on the armature gear and having a gear-side tapered surface that frictionally engages with the tapered surface; a lubricant loaded between both the tapered surfaces; and a lubricant that is screwed onto the tip of the shaft and rotated The engine is characterized by comprising an adjustment nut that pushes the armature gear to adjust the sliding torque between the two tapered surfaces, and a gear reduction mechanism that transmits the starting torque of the armature gear to a ring gear for engine starting. Starter to do. (2) an armature; an armature gear rotatably and axially movably fitted to the shaft of the armature; a shaft-side tapered portion having a shaft-side tapered surface and disposed on the shaft; and the shaft-side a gear-side tapered portion disposed on the armature gear and having a gear-side tapered surface that frictionally engages with the tapered surface; an adjustment nut that adjusts the sliding torque of the armature gear; a gear reduction mechanism that transmits the starting torque of the armature gear to a ring gear for engine starting; and a gear reduction mechanism that transmits the starting torque of the armature gear to a ring gear for starting the engine; A starter comprising: a biasing means that biases the sliding torque to increase the sliding torque. (3) The shaft-side tapered portion is fitted to the shaft so as to be integrally rotatable and movable in the axial direction, and the biasing means is fitted to the shaft and has elasticity that urges the shaft-side tapered portion in the axial direction. The starter according to claim 2, comprising a member. (4) The starter according to claim 2, wherein the biasing means comprises a disc spring fitted onto the shaft and biasing the armature gear in the axial direction. (5) The starter according to claim 2, wherein a lubricant is loaded between both the tapered surfaces.