JP3606168B2 - Yoke mounting structure of electromagnetic input clutch for automatic transmission - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an automatic transmission in which an electromagnetic input clutch is interposed between an automatic transmission and a power source instead of a torque converter, and more particularly to a structure for attaching a coil yoke of the electromagnetic input clutch. .
[0002]
[Prior art]
Regardless of whether the automatic transmission is a stepped automatic transmission or a continuously variable transmission, the automatic transmission is usually configured to input the rotation of an engine as a power source via a torque converter.
By the way, since the torque converter transmits power by fluid transmission between the input and output elements, smooth transmission is possible, but slippage occurs between the input and output elements, and a reduction in fuel efficiency is inevitable.
[0003]
Therefore, an automatic transmission has been proposed in which an input clutch such as an electromagnetic clutch or a hydraulic multi-plate clutch is provided in place of the torque converter, and the engine rotation is input via this.
By the way, as described in JP-A-10-78052 and JP-A-5-149418, when a hydraulic multi-plate clutch is used instead of the torque converter, in addition to the large size of the clutch itself, As described in JP-A-5-149418, a complicated fastening control oil passage is newly required, and the configuration of the automatic transmission becomes large and complicated, and the torque converter type automatic transmission must be redesigned significantly. In practice, electromagnetic clutches are more advantageous as input clutches than hydraulic multi-plate clutches.
[0004]
On the other hand, the electromagnetic input clutch is configured to be fastened by the electromagnetic force in the axial direction of the coil. When attaching this coil, the yoke holding the coil is attached to the inner periphery of the annular yoke holder. It is common sense to attach the coil by attaching the outer periphery to the front end opening of the transmission case.
[0005]
[Problems to be solved by the invention]
However, when the coil yoke is attached to the front end opening of the transmission case via the annular yoke holder as described above, since the inner periphery of the annular yoke holder is suspended, the attachment strength on the inner periphery of the annular yoke holder is Because it depends on the strength of the holder itself, mounting strength tends to be insufficient.
For this reason, when the input clutch is fastened by the suction by the electromagnetic force in the axial direction of the coil, the annular yoke holder is deformed by the suction reaction force, and the yoke (coil) is displaced in the axial direction, which may interfere with other parts. .
[0006]
In addition, since the displacement of the yoke (coil) in the axial direction is accompanied by the deformation of the annular yoke holder, the displacement in the radial direction is slightly unavoidable, and the coaxiality between the yoke (coil) and the transmission center axis is reduced. In addition, the air gap, which is indispensable for forming a magnetic circuit to be set between the yoke (coil) and the radially adjacent component, is also changed.
Such a change in the air gap causes a deterioration in magnetic efficiency, which causes a problem that the input clutch cannot be engaged as prescribed.
[0007]
In order to solve such a problem, it is considered that the annular yoke holder is made thick or a plurality of reinforcing ribs are erected in order to increase the strength of the annular yoke holder that determines the mounting strength on the inner periphery of the annular yoke holder. However, any of these measures increases the axial dimension of the annular yoke holder and causes an increase in weight, and miniaturization and weight reduction are fatal for the mission automatic transmission.
[0008]
In view of such a problem, the first invention described in claim 1 does not take measures against the annular yoke holder itself, but improves its attachment structure to increase the attachment strength on the inner periphery of the annular yoke holder, It is an object of the present invention to propose a yoke mounting structure for an electromagnetic input clutch for an automatic transmission in which the displacement of the coil) is prevented so that it does not interfere with other parts or change the air gap in the magnetic circuit.
[0009]
A further object of the first invention is to propose a yoke mounting structure for an electromagnetic input clutch for an automatic transmission that can achieve the above-mentioned aim with a simple and inexpensive configuration.
[0010]
The second invention described in claim 2 is the yoke mounting structure of the electromagnetic input clutch for an automatic transmission which is adapted to achieve the aim of more easily and inexpensively first invention at a suitable shape selective annular yoke holder The purpose is to propose.
[0011]
The third invention of claim 3 is intended to propose a yoke mounting structure of the electromagnetic input clutch for an automatic transmission which is adapted to further reliably avoid a change in Eagyapu during magnetic circuit.
[0012]
The fourth invention according to claim 4, suggested the effect of the third invention, the yoke mounting structure for an automatic transmission for an electromagnetic input clutch which is adapted to achieve low cost by the use of the pump housing is existing parts The purpose is to do.
[0013]
The fifth invention of claim 5 is intended to propose a yoke mounting structure of the electromagnetic input clutch for an automatic transmission which is adapted to be subjected to mounting easily and inexpensively annular yoke holder against the transmission case .
[0014]
[Means for Solving the Problems]
For the above purpose, the yoke mounting structure of the electromagnetic input clutch for an automatic transmission according to the first invention is as follows.
The outer periphery of the annular yoke holder is attached to the front end opening of the transmission case, and an electromagnetic input clutch that can be fastened by the axial electromagnetic force of the coil in the yoke attached to the inner periphery of the annular yoke holder is provided. In an automatic transmission that shifts and outputs rotation input through the input clutch,
An annular yoke holder of an electromagnetic input clutch is attached as follows.
[0015]
That is, in the first invention, when the outer periphery of the annular yoke holder is attached, the inner periphery of the annular yoke holder is pressed against the fixed portion by a preload in a direction opposite to the suction reaction force of the coil.
[0016]
Yoke mounting structure of the electromagnetic input clutch for an automatic transmission according to the second invention, in the first invention,
The annular yoke holder is made of an elastic material so as to generate the preload.
[0017]
Yoke mounting structure of the third electromagnetic input clutch for an automatic transmission according to the invention, the first invention or the second shot Oite bright,
The inner periphery of the annular yoke holder is fitted into a fixed portion and positioned in the radial direction.
[0018]
A yoke mounting structure for an electromagnetic input clutch for an automatic transmission according to a fourth invention is the third invention,
The fixed portion into which the inner periphery of the annular yoke holder is fitted is formed by a step portion formed in a pump housing installed in a front end opening of the transmission case.
[0019]
A yoke mounting structure for an electromagnetic input clutch for an automatic transmission according to a fifth invention is any one of the first to fourth inventions.
When the input clutch housing is attached to the front end opening of the transmission case, the outer periphery of the annular yoke holder is fastened together with the front end opening of the transmission case.
[0020]
【The invention's effect】
The electromagnetic input clutch is fastened by the electromagnetic force in the axial direction of the coil in the yoke attached to the inner periphery of the annular yoke holder, and the automatic transmission shifts the rotation from the power source input via the input clutch. Output.
By the way, in the first invention, when the outer periphery of the annular yoke holder is attached to the front end opening of the transmission case, the inner periphery of the annular yoke holder is pressed against the fixed portion by the preload in the direction opposite to the suction reaction force of the coil. Because it was configured as
In this attachment state, the inner periphery of the annular yoke holder is automatically fixed in the axial direction, and the attachment strength on the inner periphery of the annular yoke holder can be increased without depending on the strength of the annular yoke holder itself.
[0021]
Therefore, without increasing the axial dimension of the annular yoke holder or increasing the weight, the mounting strength on the inner circumference of the annular yoke holder can be reduced while satisfying the requirements of the automatic transmission whose mission is miniaturization and weight reduction. Can be as requested.
Thus, by increasing the mounting strength on the inner periphery of the annular yoke holder, the inner periphery of the annular yoke holder exerts a suction reaction force when the input clutch is fastened by suction by the axial electromagnetic force of the coil mounted here. Even if it is received, it does not deform, and the deformation does not cause a problem that the yoke (coil) is displaced and interferes with other parts or the air gap of the magnetic circuit is changed.
[0022]
Further in the first invention, the outer peripheral annular yoke holder inner periphery suction reaction force with the above action and effect by the configuration of being pressed to the fixed portion by preloading the opposite direction of the coil during installation of the annular yoke holder So that you can get
Without adding a complex and expensive construction, it is possible to achieve the effect of the above SL by easy single and inexpensive construction.
[0023]
In the second invention, the annular yoke holder is made of an elastic material so that the preload is generated.
The effect of the first aspect of the invention can be achieved more simply and inexpensively only by selecting an appropriate shape of the annular yoke holder.
[0024]
In the third invention, since the inner periphery of the annular yoke holder is fitted in the fixed portion and positioned in the radial direction,
Positioning in the radial direction of the yoke (coil) attached to the inner periphery of the annular yoke holder is further ensured, and a change in air gap in the magnetic circuit can be avoided more reliably.
[0025]
In the fourth aspect of the invention, the above-mentioned fixing portion that fits the inner periphery of the annular yoke holder is constituted by a step portion formed in the pump housing installed in the front end opening of the transmission case.
The effects of the third invention can be achieved at low cost by using a pump housing which is an existing part.
[0026]
In the fifth invention, the outer periphery of the annular yoke holder is fastened together with the front end opening of the transmission case when the input clutch housing is attached to the front end opening of the transmission case.
The annular yoke holder can be easily and inexpensively attached to the transmission case.
[0027]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
FIG. 1 shows a main part of an automatic transmission having a yoke mounting structure according to an embodiment of the present invention, and FIGS. 2 and 3 show an annular yoke holder used in the yoke mounting structure.
The automatic transmission is configured by housing a transmission unit (not shown) in the transmission case 21 of FIG. 1 and is, for example, a V-belt type continuously variable transmission.
[0028]
An input clutch housing 22 is attached to the front end opening of the transmission case 21, and bolts 23 are used for this attachment.
An oil pump 24 is interposed between the transmission case 21 and the input clutch housing 22, and the oil pump 24 is configured by housing an internal gear pump element in a space defined by the pump housing 25 and the pump cover 26. Use a normal gear pump.
[0029]
A fixed hollow sleeve 27 is fitted on the inner periphery of the pump cover 26, and the input shaft 28 is rotatably inserted into the hollow sleeve 27.
An electromagnetic input clutch 29 is housed in the housing 22 instead of the conventional torque converter, and the front end of the input shaft 28 protruding into the input clutch housing 22 is engaged with the electromagnetic input clutch 29 as described later. The rear end of the input shaft 28 protruding into the transmission case 21 is rotationally engaged with the transmission (not shown) in the transmission case 21.
[0030]
The input clutch 29 is an electromagnetic input clutch including an electromagnetic clutch 30, a multi-plate clutch 31 disposed on the outer periphery of the electromagnetic clutch, and a loading cam 32 disposed on the inner periphery of the electromagnetic clutch 30.
The electromagnetic clutch 30 is brought into the engaged state by attracting the armature 36 by the axial electromagnetic force generated when the coil 34 held in the yoke 33 is excited by the electric power from the conducting wire 35, and when the electromagnetic clutch 30 is engaged. The rotation of the clutch drum 38 (also serving as the drive shaft of the oil pump 24) of the multi-plate clutch 31 coupled to the crankshaft of the engine (not shown) as a power source is transmitted to the clutch hub 39 via the torsional damper 37. It shall be.
[0031]
The loading cam 32 is interposed between the clutch hub 39 of the electromagnetic clutch 30 and the clutch hub 40 of the multi-plate clutch 31 spline-fitted on the input shaft 28, and the clutch drum 38 is engaged by the above-described fastening of the electromagnetic clutch 30. When the engine rotation is input to the clutch hub 39, the loading cam 32 generates a thrust to the right in FIG. 1 in the clutch hub 40 by a cam action in which a ball rolls on an inclined surface.
This thrust pushes the clutch hub 40 of the multi-plate clutch 31 spline-fitted on the input shaft 28 in the same direction, and the outer periphery of the clutch hub 40 is caused by the above-described thrust to cause the clutch drum 38 of the multi-plate clutch 31 and The clutch pack 41 between the clutch hubs 40 is engaged, and as a result, the multi-plate clutch 31 (input clutch 29) couples the clutch hub 40 to the engine-driven clutch drum 38 and transmits the engine rotation to the input shaft 28. It will be in the fastening state.
[0032]
Here, in order to prevent dragging when the input clutch 29 is not in operation, the input clutch 29 is provided with a return spring 51. The return spring may be a coil spring as shown in the figure, or of course a disc spring.
One end of the return spring 51 is seated on the clutch hub 40, the other end is seated on the spring retainer 52, and the clutch hub 40 is biased to the left in FIG. Shall be released.
[0033]
The spring retainer 52 is attached to the shaft end of the input shaft 28. In this attachment, the spring retainer 52 is coaxially disposed on the front end surface of the input shaft 28 on the engine side, and an input clutch lubricating oil hole 28a provided in the input shaft 28 is provided. The spring retainer 52 is screwed to the front end face of the input shaft 28 by the head 53a of one bolt 53 screwed into the front end face opening.
A return spring 51 is contracted between the spring retainer 52 and the clutch hub 40 attached in this manner.
[0034]
In FIG. 1, reference numeral 54 denotes a pilot provided so as to be fitted in a recess formed in the end face of the engine crankshaft for centering between the input clutch 29 and the engine crankshaft described above. The head 53a of the bolt 53 is received in the recess 54a formed in the above.
[0035]
A one-way clutch 42 is disposed between the oil pump 24 and the loading cam 32, and the one-way clutch 42 is fitted on the input shaft 28.
Then, the annular body 43 that is rotationally engaged with the outer periphery of the one-way clutch 42 is fixed to the front end of the fixed hollow sleeve 27, and the annular body 43 and the hollow sleeve 27 are made to receive the reaction force of the one-way clutch 42. The one-way clutch 42 prevents the rotation of the input shaft 28 in the direction opposite to the engine rotation so that a hill hold function for stopping the vehicle on a slope can be achieved.
[0036]
Next, to explain the attachment structure of the yoke 33 holding the coil 34, the annular yoke holder 61 is used for this attachment.
The annular yoke holder 61 is formed by press-molding an elastic flat plate material into a shape clearly shown in FIGS. 2 and 3, and provided with a bolt hole 61 a into which the bolt 23 is inserted on the outer periphery to the front end opening of the transmission case 21. When the input clutch housing 22 is attached with the bolt 23, the outer periphery of the annular yoke holder 61 is fastened together with the front end opening of the transmission case 21.
[0037]
The inner periphery 61b of the annular yoke holder 61 is formed in a cylindrical shape so as to extend in the axial direction toward the engine side, and the yoke 33 is fitted to the outer peripheral surface of the cylindrical inner periphery 61b to prevent the snap ring 62 from coming off. To do.
The inner peripheral surface of the cylindrical inner periphery 61b of the annular yoke holder 61 is fitted into a step portion 25a formed in the pump housing 25, and the annular yoke holder 61 is positioned radially so as to be concentric with the transmission center axis. .
[0038]
The annular yoke holder 61 is connected to the input clutch housing 22 as shown by a two-dot chain line in FIG. 3 in a state where the inner peripheral surface of the cylindrical inner periphery 61b is completely fitted to the step portion 25a of the pump housing 25. When the outer periphery of the annular yoke holder 61 is fastened together with the input clutch housing 22 with the bolt 23 to the front end opening of the transmission case 21, the solid line of the annular yoke holder 61 is formed. The cylindrical inner periphery 61b is pressed against the pump housing 25 by a preload indicated by α in FIG. 3 by elastic deformation to the shape.
[0039]
In the attached state of the annular yoke holder 61 as described above, a predetermined air gap γ for forming a magnetic circuit is formed between the adjacent part and the clutch drum 38 on both sides in the radial direction of the yoke 33 on the inner periphery thereof as shown in FIG. Thus, when the coil 34 is energized, the above-described axial electromagnetic force is generated in a predetermined manner.
[0040]
To explain the operation of the automatic transmission shown in FIG. 1, the coil 34 of the electromagnetic clutch 30 is energized while it is not desired to travel and is in the non-traveling range of the neutral (N) range or the parking (P) range. First, the input clutch 29 is released by turning it off.
Therefore, the engine rotation reaching the clutch drum 38 is not transmitted to the input shaft 28, and the vehicle can be stopped.
[0041]
When the forward travel is set to the forward (D) range, or the reverse travel is desired to enter the forward (R) range, the transmission unit in the transmission case 21 is set to a corresponding power transmission enabled state.
In this state, when the coil 34 is energized to generate an axial electromagnetic force to attract the armature 36, the electromagnetic clutch 30 is engaged, and the engine rotation is transmitted from the clutch drum 38 to the clutch hub 39.
The rotation of the clutch hub 39 causes the clutch hub 40 to move to the right in FIG. 1 against the return spring 51 via the cam action of the loading cam 32, and the multi-plate clutch 31 (the electromagnetic input clutch 29 is engaged by fastening the clutch pack 41. ) Can be transmitted to the input shaft 28.
The engine rotation to the input shaft 28 is changed by the transmission unit in the transmission case 21 and transmitted to the wheels, so that the vehicle can run.
[0042]
When the electromagnetic clutch 30 that attracts the armature 36 by generating an axial electromagnetic force by energizing the coil 34 is engaged, a suction reaction force β acts on the coil 34 and the yoke 33 as shown in FIG. An attempt is made to reach the inner circumference 61 b of the holder 61.
Accordingly, since the inner periphery 61b of the annular yoke holder 61 is pressed against the pump housing 25 by the preload indicated by α in FIG. 3, the suction reaction force β is canceled by this, and the suction reaction force β is reduced to the annular yoke. It does not extend to the inner periphery 61b of the holder 61.
[0043]
Therefore, the annular yoke holder 61 is not deformed by the suction reaction force β, and the deformation causes the yoke 33 (coil 34) to be displaced from the initial mounting position and interfere with other adjacent components, or to air gap the magnetic circuit. It is possible to solve the problem that the magnetic efficiency is deteriorated by changing γ.
In addition, when the outer periphery of the annular yoke holder 61 is attached, the inner periphery 61b is pressed against the pump housing 25 by the preload α in the direction opposite to the suction reaction force β of the coil 34, so that a complicated and expensive configuration is added. The above-described effects can be achieved with a simple and inexpensive configuration.
[0044]
Further, since the annular yoke holder 61 is made of an elastic material so as to generate the preload α, the above-described effects can be achieved simply and inexpensively only by selecting the shape of the annular yoke holder 61.
[0045]
In any case, in this embodiment, when the annular yoke holder 61 is attached to the front end opening of the transmission case 21, the inner periphery 61b of the annular yoke holder 61 is automatically fixed to the pump housing 25. The attachment strength on the inner periphery 61b of the annular yoke holder 61- can be increased without relying on the reinforcement of the annular yoke holder 61 itself.
For this reason, without increasing the axial dimension of the annular yoke holder 61 or incurring an increase in weight, the downsizing and weight reduction satisfy the requirements of the automatic transmission of the mission, while the inner circumference 61b of the annular yoke holder 61 is The above-mentioned effects can be achieved by increasing the attachment strength to the required one.
[0046]
In addition, since the inner periphery 61b of the annular yoke holder 61 is fitted to the step portion 25a of the pump housing 25 and positioned in the radial direction, the diameter of the yoke 33 (coil 34) attached to the inner periphery 61b of the annular yoke holder 61 is increased. Directional positioning is further ensured, and a change in the air gap γ in the magnetic circuit can be avoided more reliably, and the above-described effect of preventing deterioration of magnetic efficiency can be further ensured.
And since the said effect is achieved by the step part 25a formed so that the inner periphery 61b of the annular yoke holder 61 might fit in the existing pump housing 25 in the front-end opening of the transmission case 21, the existing pump housing 25 is used. The effect can be achieved at low cost.
[0047]
In addition, since the outer periphery of the annular yoke holder 61 is fastened together with the front end opening of the transmission case when the input clutch housing 22 is attached to the front end opening of the transmission case 21 with the bolts 23, The annular yoke holder 61 can be easily and inexpensively attached.
[Brief description of the drawings]
FIG. 1 is a longitudinal sectional side view of an essential part showing an automatic transmission having a yoke mounting structure according to an embodiment of the present invention.
FIG. 2 is a front view of an annular yoke holder used in the same embodiment.
FIG. 3 is an enlarged cross-sectional view showing a mounting state of the annular yoke holder together with its free shape.
[Explanation of symbols]
21 Transmission case 22 Input clutch housing 23 Bolt 24 Oil pump 25 Pump housing 25a Step portion 26 Pump cover 27 Hollow sleeve 28 Input shaft 29 Electromagnetic input clutch 30 Electromagnetic clutch 31 Multi-plate clutch 32 Loading cam 33 Yoke 34 Coil 35 Conductor 36 Armature 37 Torsional damper 38 Clutch drum 39 Clutch hub 40 Clutch hub 41 Clutch pack 42 One-way clutch 43 Annular body 51 Return spring 52 Spring retainer 53 Bolt 54 Pilot 61 Annular yoke holder 61a Bolt hole 61b Cylindrical inner circumference 62 Snap ring α Preload β Suction reaction force γ Air gap

Claims (5)

The outer periphery of the annular yoke holder is attached to the front end opening of the transmission case, and an electromagnetic input clutch that can be fastened by the electromagnetic force in the axial direction of the coil in the yoke attached to the inner periphery of the annular yoke holder is provided. In an automatic transmission that shifts and outputs rotation input through the input clutch,
An electromagnetic type for an automatic transmission , wherein the inner periphery of the annular yoke holder is configured to be pressed against a fixed portion by a preload opposite to the suction reaction force of the coil when the outer periphery of the annular yoke holder is attached. Input clutch yoke mounting structure. 2. The yoke mounting structure for an electromagnetic input clutch for an automatic transmission according to claim 1 , wherein the annular yoke holder is made of an elastic material so that the preload is generated. According to claim 1 or 2, yoke mounting structure of the annular yoke electromagnetic input clutch for an automatic transmission, characterized in that the inner circumference of the holder fitted to the fixing portion is positioned in the radial direction. 4. The automatic transmission according to claim 3 , wherein the fixed portion with which the inner periphery of the annular yoke holder is fitted is configured by a step portion formed in a pump housing installed in a front end opening of the transmission case. Yoke mounting structure for electromagnetic input clutch for machine. In any one of claims 1 to 4, wherein said that the outer periphery of the annular yoke holder was fastened to the front end opening of the speed change transmission case when mounting the input clutch housing to the front end opening of the transmission case automatic Yoke mounting structure for electromagnetic input clutch for transmission.

Images