JP3592752B2 - Power transmission switching device - Google Patents

Description

[0001]
[Industrial applications]
The present invention relates to a power transmission switching device used for, for example, a power take-out device for a vehicle, and more particularly to a power transmission switching device that switches power transmission using an electromagnetic attraction force of a solenoid.
[0002]
[Prior art]
2. Description of the Related Art Conventionally, in garbage collection vehicles and various industrial vehicles, hydraulic power devices for various operations are driven by using engine power, and a power transmission switching device for switching power transmission is used to take out the power. Have been.
[0003]
For example, in Japanese Patent Application Laid-Open No. 59-120520, an output shaft is rotatably supported by a gear box, and a clutch hub is provided on the outer periphery of the output shaft. On the outer periphery of the output shaft, an input member is rotatably supported at a portion adjacent to the clutch hub, and an outer spline is provided on the outer periphery of the input member.
[0004]
A clutch sleeve having an inner spline that can mesh with the clutch hub and the outer spline is mounted on the outer periphery of the output shaft so as to be movable in the axial direction. The clutch sleeve is engaged only with the clutch hub by the spring force of the spring. It is urged in a direction to separate from the outer spline, and power transmission between the input member and the output shaft is normally cut off.
[0005]
The switching of the clutch sleeve is performed not by manual operation but by an electromagnetic solenoid. That is, by the electromagnetic attraction force of the electromagnetic solenoid, the clutch sleeve is moved to the outer spline side against the spring force of the spring, and the inner spline of the clutch sleeve is engaged with both the outer spline and the clutch hub, thereby driving the input member. The force is transmitted to the output shaft.
[0006]
When driving the clutch sleeve, it is necessary to supply a current to the electromagnetic solenoid for a long time. However, if a large current is continued to flow for a long time, the coil of the solenoid is burned due to heat generation. Therefore, in this conventional example, a constant current flows continuously until a clutch sleeve requiring a large suction force engages with the clutch hub, and after the clutch is connected, a pulse current flows to generate heat as much as possible. Was small.
[0007]
[Problems to be solved by the invention]
However, in the case of the prior art described above, although a pulse current is supplied after the clutch sleeve is connected to suppress heat generation, when the magnetomotive force is increased, it is necessary to shorten the interval between the pulse currents. Fever increases.
[0008]
Due to this heat generation, the coil resistance increases, and if re-operation is performed immediately thereafter, the suction force required for the operation cannot be obtained. That is, the rate of change of resistance (R2 / R1) due to heat generation of the coil is (R2 / R1) = (234.5 + T2) / (234.5 + T1) in the case of a copper winding. Here, T1 is the temperature before heat generation, T2 is the temperature after heat generation, R1 is the coil resistance before heat generation, and R1 is the coil resistance after heat generation.
[0009]
Assuming that the current and the attraction force before the heat generation are I1 and F1, and the current and the attraction force after the heat generation are I2 and F2, the current change rate (I2 / I1) is (I2 / I1) = (R1 / R2). It becomes.
[0010]
Since the attractive force is proportional to the square of the magnetomotive force, the rate of change of the attractive force (F2 / F1) is (F2 / F1) = (I2 / I1) ² = (R1 / R2) ² = ｛(234.5 + T1) ) / (234.5 + T2)｝ ² .
[0011]
Assuming that T1 = 20 [° C.] (normal temperature), the change rate of the suction force (F2 / F1) = {254.5 / (234.5 + T2)} ² .
[0012]
As a result, the relationship between the coil temperature and the rate of change of the attraction force is as shown in FIG.
[0013]
In order to suppress heat generation, the number of windings must be increased to suppress the current and increase the magnetomotive force, and the size of the solenoid increases, and as a result, the power transmission switching device itself also increases in size.
[0014]
Further, there has been a problem that a control circuit for performing pulse control becomes complicated and costs increase.
[0015]
The present invention has been made in order to solve the above-mentioned problems of the prior art, and it is an object of the present invention to prevent coil seizure and enable smooth clutch switching without increasing the size of a solenoid. Another object of the present invention is to provide a power transmission switching device having a simple control structure.
[0016]
[Means for Solving the Problems]
In order to achieve the above object, in the present invention, a gear box, an output shaft rotatably supported by the gear box, a clutch hub provided on the outer periphery of the output shaft, An input member rotatably supported at a portion adjacent to the clutch hub, an outer spline provided on the outer periphery of the driving body, a clutch sleeve having an inner spline that can mesh with the clutch hub and the outer spline, and a clutch sleeve. Urging means for engaging only with the clutch hub and urging in a direction to disengage from the outer spline to cut off the transmission of power between the input member and the output shaft; and an outer spline for urging the clutch sleeve against the urging force of the urging means. Side so that the inner spline of the clutch sleeve meshes with the outer spline and the clutch hub so as to straddle and transmit the driving force of the input member to the output shaft. An operating coil for obtaining a suction force while moving the clutch sleeve to a position where the clutch sleeve engages with the outer spline against the urging force of the urging means; and an outer spline. And a holding coil for obtaining a suction force sufficient to hold at the meshing position.
[0017]
Also, when the clutch sleeve is moved to the position where it engages with the outer spline, only the operating coil is moved using the attraction force of both the operating coil and the holding coil, and the clutch sleeve is moved to the position where it engages with the outer spline. It is characterized in that the holding is performed only by the attraction force of the holding coil.
[0018]
[Action]
In the clutch device with an electromagnetic solenoid according to the present invention, the clutch sleeve is normally meshed only with the clutch hub by the urging force of the urging means, and is separated from the outer spline of the input member so that no power is transmitted. The input member is idling with respect to the output shaft.
[0019]
When transmitting power, first, a current is caused to flow through an operation coil of an electromagnetic solenoid to generate a magnetomotive force, and the clutch sleeve is moved to a position where the clutch sleeve engages with the outer spline. At this time, the holding coil may or may not be energized. The clutch sleeve moves toward the outer spline while maintaining the meshing state with the clutch hub.
[0020]
When the clutch sleeve meshes with the outer spline, the power supply to the operating coil is stopped, and the clutch sleeve is held only by the electromagnetic attraction of the holding coil.
[0021]
Therefore, the energization of the operating coil can be easily controlled by using a timer, for example, since the energization may be cut off after energizing for a predetermined time.
[0022]
When the power supply to the holding coil is stopped, the clutch sleeve is detached from the outer spline of the input member again by the urging force of the urging means, and the clutch sleeve is brought into a meshing state with only the clutch hub.
[0023]
【Example】
Hereinafter, the present invention will be described with reference to the illustrated embodiments. 1 and 2 show a power transmission switching device according to one embodiment of the present invention. 1 shows a power transmission cutoff state, and FIG. 2 shows a power transmission state.
[0024]
The power transmission switching device 1 includes an internally hollow gear box 2, an output shaft 3 rotatably mounted on the gear box 2, a clutch hub 4 provided on the outer periphery of the output shaft 3, and a clutch hub on the outer periphery of the output shaft 3. An input member 5 rotatably supported at a position adjacent to the input member 4, an outer spline 6 provided on the outer periphery of the input member 5, and a clutch sleeve 8 having an inner spline 7 meshable with the clutch hub 4 and the outer spline 6. And an electromagnetic solenoid 9 for reciprocatingly driving the clutch sleeve 8.
[0025]
The output shaft 3 is rotatably supported at both axial ends of the gear box 2 via bearings 10, and one end of the output shaft 3 projects outside the gear box 2 as an output end 11. The output end 11 has a tapered tapered shape, a flange 12 for a joint is fixed, and rotation is prevented by a half-moon key 13. In addition, a seal member 27 for preventing dust from entering the gear box 2 from the outside is provided at an opening on the output end side of the gear box 2.
[0026]
The portion of the output shaft 3 located inside the gear box 2 includes a large-diameter portion 14 on the output end side and a small-diameter portion 15 on the non-output end side. It is engraved. On the other hand, an annular input member 5 is rotatably mounted on the outer periphery of the small diameter portion 15 via a slide bearing 16. The input member 5 is mounted between the large diameter portion 14 and the bearing 10 via a spacer 17 so as not to move in the axial direction.
[0027]
Provided on the outer periphery of the input member 5 are an input gear 18 meshed with a gear on the power source side (not shown) and an outer spline 6 constituting a clutch mechanism located at a portion of the output shaft 3 adjacent to the clutch hub 4. Have been. The clutch hub 4 and the outer spline 6 have the same diameter and the same pitch. The input of the power to the input member 5 can be performed by using a wrapping transmission mechanism such as a belt or a chain in addition to the gear mechanism.
[0028]
The clutch sleeve 8 is also an annular member, and is provided with an outer spline 6 and an inner spline 7 meshable with the clutch hub 4 on the inner peripheral surface thereof.
[0029]
A shift arm 20 reciprocally driven in the axial direction by the electromagnetic solenoid 9 is engaged with an engagement groove 19 provided on the outer periphery of the clutch sleeve 8.
[0030]
The shift arm 20 is fixed to a shift rod 21 arranged in parallel with the output shaft 3 by a pin 22. Both ends of the shift rod 21 are slidably guided and supported by rod support holes 23 provided in both end walls of the gear box 2. A seal member 26 for sealing leakage of oil or the like from the rod support hole 23 to the electromagnetic solenoid 9 is provided on an end wall of the rod support hole 23 on the side where the electromagnetic solenoid 9 is attached.
[0031]
The clutch sleeve 8 is urged between the shift arm 20 and the end wall of the gear box 2 in a direction of engaging only with the clutch hub 4 and separating from the outer spline 6 between the shift arm 20 and the end wall of the gear box 2. A spring 25 as an urging means for interrupting power transmission between the input member 5 and the output shaft 3 is mounted in a state compressed in the axial direction.
[0032]
A movable iron core 93 of the electromagnetic solenoid 9 is operatively connected to one end of the shift rod 21 via a connecting rod 932.
[0033]
The electromagnetic solenoid 9 has a schematic configuration in which a fixed iron core 92 as a fixed member, a plunger 93 as a movable member provided coaxially opposed to the fixed iron core 92, and a structure surrounding the fixed iron core 92 and the plunger 93. And a case 95 surrounding the electromagnetic coil 94 and forming a magnetic path between the fixed iron core 92 and the plunger 93 when the electromagnetic coil 94 is excited. Fixed to.
[0034]
The fixed iron core 92 includes a columnar portion 921 and a disk-shaped upper plate portion 922 fixed to one end of the columnar portion 921 and extending in the radial direction, and faces the plunger 93 of the columnar portion 921. The end on the side has a truncated cone shape.
[0035]
The plunger 93 is provided so as to be coaxially opposed to the fixed iron core 92, and is capable of moving a stroke from a position away from the fixed iron core 92 by a predetermined distance to a position where the plunger 93 is sucked and held by the fixed iron core 92. Is set according to the moving range of the clutch sleeve 8. At the end of the plunger 93 on the side facing the fixed iron core 921, a truncated conical recess is formed such that the truncated conical projection of the fixed iron core 921 fits therein. The plunger 93 is integrally provided with a connecting rod 932 connected to the shift rod 21 by the connecting pin 28.
[0036]
The electromagnetic coil 94 generates a necessary magnetomotive force at a position where the operating coil 941 that generates a required magnetomotive force during movement of the clutch sleeve 8 and the outer spline 18 of the clutch sleeve 8 (power transmission state). And a holding coil 942. The operating coil 941 and the holding coil 942 are arranged in series in the axial direction, wound around one bobbin 943, and the outer periphery is covered with a resin mold 944. The operating coil 941 and the holding coil 942 are independent of each other, and lead wires (not shown) extend independently.
[0037]
The case 95 is a hollow cylindrical member having a bottom with a plunger guide 952 attached to the bottom where the resin mold 944 is accommodated. The outer end of the upper plate 922 of the fixed iron core 92 is fixed to the open end. The plunger guide 952 is a cylindrical member fixedly inserted into an inner periphery of an opening provided at the bottom of the case. The plunger guide 952 is mounted on the bracket 24, and the bracket 24 is provided with a stopper 955 for positioning the plunger 93. In short, the position of the clutch sleeve 8 that is urged by the spring force of the spring 25 of the stopper portion 955 is determined.
[0038]
Next, the operation of the present invention will be described.
[0039]
When switching from the power transmission cutoff state to the power transmission state, the operating coil 941 and the holding coil 942 are energized simultaneously. Then, the plunger 93 is magnetically attracted to the fixed iron core 92, and the clutch sleeve 8 is moved to the outer spline 6 side of the input member 5 via the connecting rod 932, the shift rod 21, and the shift arm 20 against the spring force of the spring 25. Moving. When the clutch sleeve 8 is moved to the meshing position with the external spline 6 by energizing for a predetermined time, only the operating coil 941 is turned off and the external spline meshing state is maintained by energizing the holding coil 942. The energization of the operating coil 941 and the holding coil 942 does not have to be performed simultaneously, but it is sufficient that the energizing is performed at least when the operating coil 941 is turned off.
[0040]
The control of the operating coil 91 may be turned off after a predetermined time has elapsed by using a timer, and the control configuration can be extremely simplified. Also, without using a timer, the amount of movement of any one of the plunger, the connecting rod 932, the shift rod 21, the shift arm 20, and the clutch sleeve 8 is detected by various sensors or the like, and the sensor is turned off when it moves to a predetermined position. In any case, the control configuration itself becomes very simple.
[0041]
During the stroke, in order to satisfy the thrust at the beginning of pulling on the operating coil 941, a large current is applied to complete the stroke, so that a magnetomotive force necessary for the thrust is generated. The operating coil 941 has a low resistance value that does not cause burnout until the stroke is completed.
[0042]
Then, when the stroke is completed and the plunger 93 is attracted to the fixed iron core 92, the power supply to the operating coil 941 is stopped, and the plunger 3 is sucked and held only by the holding coil 942. The holding coil 942 has a resistance value such that the holding coil 942 has such a low current as not to be burned even if the stroke is held continuously for a long time.
[0043]
Since the energizing coil 941 is energized only during the stroke, a large current can be supplied to the extent that it does not burn out, and a large thrust can be obtained.
[0044]
On the other hand, at the meshing position between the clutch sleeve 8 and the outer spline 6, the distance between the fixed iron core 92 and the plunger 93 is in a contact state or a close state, so that a large holding force can be obtained even at a low current value. Even if it is kept for a long time, the calorific value is small and there is no risk of burning.
[0045]
As described above, by controlling the electromagnetic coil 94 separately with the operating coil 941 and the holding coil 42, a large thrust can be obtained during a stroke while being small, and it can be continuously held for a long time. It becomes.
[0046]
【The invention's effect】
The present invention has the above-described configuration and operation, and differentiates the function of the electromagnetic coil for moving the clutch sleeve into the operating coil and the holding coil, and only the operating coil or the operating coil and the holding coil during the movement. Utilizing both electromagnetic attraction of the coil, when the meshing state with the outer spline was reached, the energization of the operating coil was cut off and the clutch sleeve was held only by the holding coil, so one coil It is not necessary to increase the size when increasing the magnetomotive force as in the case where a pulse wave is applied to suppress and generate heat, and a large suction force can be obtained during a stroke while being small, and It can be held continuously for a long time.
[0047]
In addition, the control configuration only needs to be turned off after the operation coil is energized for a predetermined time, which is extremely simple as compared with the conventional pulse control.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view showing an off state of a solenoid of a power transmission switching device according to one embodiment of the present invention.
FIG. 2 is a sectional view showing an ON state of a solenoid of the apparatus of FIG. 1;
FIG. 3 is a graph showing a relationship between a coil temperature and a rate of change of an attraction force.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Power transmission switching device 2 Gear box 3 Output shaft 4 Clutch hub 5 Input member 6 Outer spline 7 Inner spline 8 Clutch sleeve 9 Electromagnetic solenoid 10 Bearing 11 Output end 12 Joint flange 13 Half moon key 14 Large diameter part 15 Small diameter part 16 Sliding bearing 17 Spacer 18 Input gear 20 Shift arm 21 Shift rod 22 Pin 23 Rod support hole 24 Bracket 25 Spring (biasing means)
26, 27 Sealing member 28 Connecting pin 91 Solenoid device 92 Fixed iron core 921 Cylindrical portion 922 Upper plate portion 93 Plunger 932 Connecting rod 94 Electromagnetic coil 941 Operating coil 942 Holding coil 943 Bobbin 944 Resin mold 95 Case 952 Plunger guide 955 Stopper

Claims (1)

A gear box, an output shaft for power output rotatably supported by the gear box,
A clutch hub provided around the output shaft,
An input member for power input rotatably supported at a position adjacent to the clutch hub on the outer periphery of the output shaft,
An outer spline provided on the outer periphery of the input member,
A clutch sleeve having an inner spline that can mesh with the clutch hub and the outer spline,
Urging means for urging the clutch sleeve only with the clutch hub and disengaging from the outer spline to cut off power transmission between the input member and the output shaft;
By moving the clutch sleeve meshing with the clutch hub against the biasing force of the biasing means in the axial direction toward the outer spline, the inner spline of the clutch sleeve meshes across the outer spline and the clutch hub, and the input member has and an electromagnetic solenoid which is transmitted to the output shaft of the driving force,
The electromagnetic solenoid has an operating coil for obtaining a suction force while moving the clutch sleeve to a position where the clutch sleeve engages with the outer spline against the urging force of the urging means,
And a holding coil for obtaining the attraction force enough to hold at the meshing position between the outer spline provided,
When the clutch sleeve is moved to the engagement position with the outer spline, it is moved using only the operating coil or the suction force of both the operation coil and the holding coil, and the clutch sleeve is held at the engagement position with the outer spline A power transmission switching device, wherein the power transmission switching device is held only by the attraction force of the holding coil .

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