JP2007211929A - Forward and reverse changing mechanism - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a forward and reverse changing mechanism to curtail a fastening element so as to reduce cost and size. <P>SOLUTION: The forward and reverse changing mechanism is provided with a fluid transmission mechanism having a pump impeller 104 connected to an input shaft 102, a turbine runner 108 capable of being connected to a turbine brake mechanism TBR via a turbine shaft 106, and a stator 114 capable of being connected to a stator brake mechanism SBR via a stator shaft 110, and an output shaft 120 arranged between the turbine shaft 106 and the stator shaft 110, a first two-way clutch 130 arranged between the output shaft and the stator shaft 110, and a second two-way clutch 140 arranged between the output shaft 120 and the turbine shaft 106. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a forward / reverse switching mechanism, and more particularly to a forward / reverse switching mechanism suitable for use in an automatic transmission including a continuously variable transmission.

  In general, in an automatic transmission for a vehicle, for example, a belt type continuously variable transmission (CVT), a forward / reverse switching device including a planetary gear device or the like is used to switch the vehicle's forward / reverse travel. By the way, since such a planetary gear device has a complicated mechanism and is expensive, a mechanism capable of switching forward and backward without using such a planetary gear device has also been proposed. For example, the thing of patent document 1 is known.

  In the one disclosed in Patent Document 1, a turbine shaft of a torque converter is connected to a pulley input shaft of a CVT via a forward clutch, and a reverse brake is provided on the turbine shaft. In addition, the stator shaft of the torque converter is connected to the pulley input shaft via the reverse clutch and is connected to the one-way clutch via the stator clutch, and the forward clutch and the stator clutch are engaged at the forward stage. At the same time, the reverse brake and reverse clutch are released, and the driving force is transmitted from the turbine shaft to the pulley input shaft. At the reverse stage, the reverse brake and reverse clutch are engaged and the forward clutch and stator clutch are released. Thus, the driving force is transmitted from the stator shaft to the pulley input shaft.

JP 2002-340139 A

  However, in the forward / reverse switching mechanism described in Patent Document 1, since it is not necessary to use a planetary gear device, the weight can be reduced and the cost can be reduced correspondingly. However, the forward clutch, the reverse clutch, and the stator can be reduced. Three clutches of the clutch and one reverse brake are required, and a total of four fastening elements are required, which is not sufficient in terms of cost reduction and compactness.

  SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a forward / reverse switching mechanism that solves the above-described problems and reduces the number of fastening elements to enable cost reduction and compactness.

  A forward / reverse switching mechanism that achieves the above object is a pump impeller connected to an input shaft, a turbine runner that can be connected to a turbine brake mechanism via a turbine shaft, and a stator shaft to a stator brake mechanism. A fluid transmission mechanism having a stator that can be connected via the first shaft, an output shaft disposed between the turbine shaft and the stator shaft, and a first disposed between the output shaft and the stator shaft. A two-way clutch and a second two-way clutch disposed between the output shaft and the turbine shaft are provided.

  According to the forward / reverse switching mechanism according to one aspect of the present invention, the forward / reverse switching mechanism is configured by using the first and second two-way clutches and the two fastening elements of the turbine brake mechanism and the stator brake mechanism as the fastening elements. Therefore, it is possible to obtain forward, reverse, and neutral states with few fastening elements, enabling cost reduction and downsizing, and forward / reverse switching control is also easy.

  Here, the first and second two-way clutches operate so that the turbine shaft and the stator shaft do not rotate to the same direction side as the input shaft with respect to the output shaft during the braking operation of the stator brake mechanism, It is preferable that the turbine shaft and the stator shaft are configured to operate so as not to rotate in a direction opposite to the input shaft with respect to the output shaft during a braking operation of the turbine brake mechanism.

  According to this configuration, the rotation allowable direction of the first and second two-way clutches is switched by the brake operation of the stator brake mechanism or the turbine brake mechanism, and therefore the rotation direction of the output shaft is switched.

  In addition, the stator brake mechanism is braked and the turbine brake mechanism is not operated when moving forward, the stator brake mechanism is not operated and the turbine brake mechanism is braked when moving backward, and the turbine brake mechanism is operated when neutral. Both the stator brake mechanism and the turbine brake mechanism may be inactivated.

  According to this configuration, a range of forward / reverse and neutral can be formed. In particular, during neutral, both the stator brake mechanism and the turbine brake mechanism are inoperative, so that the load on the control hydraulic pressure supply system is reduced.

  Further, when the vehicle is moving forward, the stator brake mechanism is braked and the turbine brake mechanism is not operated. When the vehicle is moved backward, the stator brake mechanism is not operated and the turbine brake mechanism is braked. When the vehicle is neutral, Both the stator brake mechanism and the turbine brake mechanism may be braked.

  According to this configuration, the forward / reverse and neutral ranges can be formed. In particular, since the stator brake mechanism and the turbine brake mechanism are both braked at the neutral time, the turbine brake is used when switching from the neutral to the forward range. It is sufficient to make the mechanism brake inoperative, and the shock can be reduced.

  Further, the output shaft may be spline fitted to the input shaft of the belt type continuously variable transmission so as to be movable in the axial direction.

  The best mode for carrying out the present invention will be described below with reference to the drawings. FIG. 1 is a skeleton diagram showing an embodiment in which a forward / reverse switching mechanism according to the present invention is applied to a forward / reverse switching device for a belt type continuously variable transmission (hereinafter referred to as CVT).

  As shown in FIG. 1, the forward / reverse switching mechanism 100 incorporated as a forward / reverse switching device in the CVT is connected to a pump impeller 104 connected to an input shaft 102 that rotates integrally with a crankshaft of the engine ENG, and to a turbine shaft 106. A fluid transmission mechanism 115 which is a torque converter including a turbine runner 108 and a stator 114 connected to a hollow stator shaft 110 via a one-way clutch 112. The turbine runner 108 can be connected to a turbine brake mechanism TBR via a turbine shaft 106 that passes through a primary shaft that is an input shaft of a CVT described later, and the stator 114 is connected to the stator brake mechanism via the stator shaft 110. It is possible to connect to SBR. Here, each of the turbine brake mechanism TBR and the stator brake mechanism SBR includes a hydraulic actuator in which supply hydraulic pressure from a control hydraulic pressure supply system (not shown) is switched and controlled by a control signal from an ECU 200 described later, and includes a turbine shaft 106 and a stator. It is comprised so that the fastening fixed state and releasing state with respect to stationary members, such as a CVT casing, of the axis | shaft 110 may be obtained. Note that the piston in the hydraulic actuator of the stator brake mechanism SBR is denoted by reference numeral 116 in FIG.

  A hollow output shaft 120 is coaxially disposed as an output shaft of the forward / reverse switching mechanism 100 between the turbine shaft 106 and the stator shaft 110. The hollow output shaft 120 is a CVT described later. The primary shaft that is the input shaft is splined so as to be movable in the axial direction.

  Further, between the output shaft 120 and the stator shaft 110, that is, on the outer diameter side of the output shaft 120, the first two-way clutch 130 and between the turbine shaft 106 and the output shaft 120, that is, the inner diameter of the output shaft 120. A second two-way clutch 140 is arranged on each side. The first sprag 132 of the first two-way clutch 130 is positioned in the axial direction with respect to the stator shaft 110, and the second sprag 142 of the second two-way clutch 140 is positioned in the axial direction with respect to the turbine shaft 106. Yes. The first and second two-way clutches 130 and 140 each include an inner ring and an outer ring, and the first and second sprags 132 and 142 are generally disposed between them. However, in some cases, these inner ring and outer ring may be omitted. In the present embodiment, the following description will be made assuming that these inner and outer rings are omitted.

  Next, switching means for switching the driving force transmission direction or the idling possible direction of the first and second two-way clutches 130 and 140 will be described. The switching means in the present embodiment is configured as described below. That is, an annular first support plate 122 is fixed to the outer diameter side of the output shaft 120, and a pressing plate 124 as a pressing member is fixed to the inner diameter side thereof. Note that the pressing plate 124 only needs to have a function of pressing a second support plate 154 to be described later. Therefore, the pressing plate 124 does not need to be formed on the plate, and may be configured by a plurality of claw members or the like.

  One end of a plurality of first springs 150 is supported on the annular first support plate 122 at equal intervals in the circumferential direction, and the other ends of the plurality of first springs 150 are annular. The first pressing plate 152 is attached. The annular first pressing plate 152 can be brought into contact with the first sprag 132 of the first two-way clutch 130.

  On the other hand, an annular second support plate 154 is spline-fitted so as to be axially movable with respect to the turbine shaft 106, and the annular second support plate 154 is similar to the first support plate 122. One end of the plurality of second springs 156 is supported at equal intervals in the circumferential direction, and the other end of the plurality of second springs 156 is attached to the annular second pressing plate 158. The annular second pressing plate 158 can be brought into contact with the second sprag 142 of the second two-way clutch 140.

  In addition, a proximal end portion of a link member 160 is connected to the piston 116 in the hydraulic actuator of the stator brake mechanism SBR described above, and the distal end portion of the link member 160 is fixed to the outer diameter side of the output shaft 120. In addition, a fork 162 that engages with the outer periphery of the annular first support plate 122 in an axially driveable manner is provided.

  As described above, the belt-type continuously variable transmission CVT is arranged in parallel with the primary shaft PS that is the input shaft, in which the hollow output shaft 120 is spline-fitted so as to be movable in the axial direction. Secondary shaft SS, primary-side variable pulley PVP and secondary-side variable pulley SVP, and belt B wound around both variable pulleys PVP and SVP, respectively.

  Reference numeral 200 denotes an electronic control unit (hereinafter referred to as ECU) that controls the belt type continuously variable transmission CVT including the forward / reverse switching mechanism 100, and includes an arithmetic processing unit (CPU or MPU) and a storage device (RAM and ROM). ) And a microcomputer mainly including an input / output interface.

  For this ECU 200, a pump rotational speed sensor capable of detecting the rotational speed of the pump impeller 104 or the input shaft 102, the rotational speed of the turbine runner 108 or the turbine shaft 106, and the rotational speed of the stator 114, respectively. Signals from the rotational speed sensor and the stator rotational speed sensor are input. In addition, as information necessary for controlling the belt type continuously variable transmission CVT, for example, a shift signal based on an operation position of a shift lever (not shown), a vehicle speed based on the rotation speed of the secondary shaft SS that is an output shaft of the CVT Information such as a signal and an accelerator opening signal proportional to the amount of depression of an unillustrated accelerator pedal is input. In the storage device, a desired hydraulic control value corresponding to the above information is obtained in advance through experiments or the like, and is mapped and stored.

  Here, the first and second two-way clutches 130 and 140 used in the present embodiment will be further described with reference to FIG. As described above, the first two-way clutch 130 is disposed between the stator shaft 110 and the output shaft 120 and has a plurality of first sprags 132 at equal intervals in the circumferential direction. On the other hand, as described above, the second two-way clutch 140 is arranged between the turbine shaft 106 and the output shaft 120 and has a plurality of second sprags 142 at equal intervals in the circumferential direction. In the present embodiment, the first sprag 132 and the second sprag 142 are pressed by the annular first pressing plate 152 and the second pressing plate 158, respectively, by the operation of the switching means described above. In addition, when the pressure is released, the driving force transmission direction of the stator shaft 110 and the turbine shaft 106 with respect to the output shaft 120 or the idling direction can be switched.

  More specifically, in the state shown in FIG. 2, neither the first pressing plate 152 nor the second pressing plate 158 is in contact with the first sprag 132 and the second sprag 142, and the stator Both the shaft 110 and the turbine shaft 106 can idle in a clockwise direction with respect to the output shaft 120 (as viewed in the direction of arrow A in FIG. 1, hereinafter also referred to as a forward rotation direction). In FIG. 2, the idling direction of the stator shaft 110 with respect to the output shaft 120 is indicated by an arrow Scw, and the idling direction of the turbine shaft 106 with respect to the output shaft 120 is indicated by an arrow Tcw. Thus, as will be described later, the first and second two-way clutches 130 and 140 are configured such that the turbine shaft 106 and the stator shaft 110 are in the same direction as the input shaft 102 relative to the output shaft 120 when the stator brake mechanism SBR is braked. The turbine shaft 106 and the stator shaft 110 operate so as not to rotate in the direction opposite to the input shaft 102 relative to the output shaft 120 during the braking operation of the turbine brake mechanism TBR.

  Here, an example of the control procedure in the present embodiment will be described with reference to the control routine shown in the flowchart of FIG. This control is executed at predetermined intervals. When control is started, a shift signal is acquired in step S301. Specifically, a signal indicating forward D, reverse R, or neutral N is acquired based on the operation position of the shift lever. Then, the process proceeds to the next step S302, and it is determined whether or not the shift signal acquired in step S301 is forward D. When the shift signal is forward D, the process proceeds to step S303, where the hydraulic pressure of the hydraulic actuator of the turbine brake mechanism TBR is released, that is, the turbine brake mechanism TBR is deactivated and the hydraulic actuator of the stator brake mechanism SBR. The hydraulic pressure is applied to the piston 116 and the stator brake mechanism SBR is brought into the engaged state, that is, the operating state, and this control routine is ended. Thus, in this state, as will be described later, the forward / reverse switching mechanism 100 is set to the forward D state.

  By the way, when it is determined in step S302 that the vehicle is not forward D, the process proceeds to step S304, and it is determined whether or not the shift signal acquired in step S301 is reverse R. When the shift signal is reverse R, the process proceeds to step S305, where the hydraulic pressure of the hydraulic actuator of the stator brake mechanism SBR is released, and a predetermined hydraulic pressure is applied to the hydraulic actuator of the turbine brake mechanism TBR, and the turbine brake mechanism TBR is engaged. The control routine is terminated. Thus, in this state, as will be described later, the forward / reverse switching mechanism 100 is in the reverse R state.

  On the other hand, when the shift signal is not reverse R in step S304, the process proceeds to step S306, and it is determined whether or not the shift signal is neutral N. When the shift signal is not neutral N, this control routine is once terminated. When the shift signal is neutral N, the process proceeds to step S307, where the hydraulic pressure of the hydraulic actuator of the stator brake mechanism SBR is released and the hydraulic pressure of the hydraulic actuator of the turbine brake mechanism TBR is also released, and this control routine ends. The Thus, in this state, as will be described later, the forward / reverse switching mechanism 100 is set to the neutral N state.

  Next, the operation of the stator brake mechanism SBR, the turbine brake mechanism TBR and the first and second two-way clutches 130 and 140 in each of the forward D state, the reverse R state and the neutral N state described above will be described with reference to FIGS. This will be described with reference to FIG.

  First, assuming that the direction of torque input from the engine ENG to the pump impeller 104 of the torque converter 115 via the input shaft 102 is clockwise as indicated by an arrow Pcw in FIG. 4A, the turbine brake mechanism TBR. When the hydraulic pressure of the hydraulic actuator is released, in other words, in the brake non-operating state, the turbine runner 108 and thus the turbine shaft 106 also rotate clockwise.

  Therefore, as described above, during forward D, the hydraulic pressure is applied to the piston 116 of the hydraulic actuator of the stator brake mechanism SBR to perform a brake operation, in other words, the stator brake mechanism SBR is engaged, and at the same time the hydraulic pressure of the turbine brake mechanism TBR. The hydraulic pressure of the actuator is released, in other words, the brake is not activated. Then, as shown in FIG. 4 (A), the link member 160 connected to the piston 116 is also moved in the axial direction (right direction in the figure), and the output shaft 120 is passed through the fork 162 provided at the tip portion thereof. The annular first support plate 122 fixed to the outer diameter side of the first shaft 122 is moved in the axial direction (right direction in the drawing) together with the output shaft 120. As a result, the annular first pressing plate 152 is pressed against the scrub 132 of the first two-way clutch 130 via the first spring 150. At the same time, a pressing plate 124 as a pressing member fixed on the inner diameter side of the output shaft 120 is also moved in the axial direction, and is an annular second support plate that is spline-fitted to the turbine shaft 106 so as to be movable in the axial direction. 154 is moved in the axial direction. Then, the annular second pressing plate 158 is pressed against the second sprag 142 of the second two-way clutch 140 via the second spring 156.

  When the annular first pressing plate 152 is pressed against the scrub 132 of the first two-way clutch 130 via the first spring 150, the first spring 150 is supported by the annular first support plate 122. Since it rotates integrally with the output shaft 120, the first sprag 132 of the first two-way clutch 130 receives a force in the same rotational direction as that of the output shaft 120, and its posture is changed as shown in FIG. . Then, the idling direction of the stator shaft 110 becomes a counterclockwise arrow Sccw, and the first two-way clutch 130 can idly rotate with respect to the output shaft 120.

  On the other hand, when the second pressing plate 158 is pressed against the second sprag 142 of the second two-way clutch 140 via the second spring 156, an annular second support that supports the second spring 156 is provided. Since the plate 154 is spline-fitted to the turbine shaft 106 so as to rotate integrally therewith, the second sprag 142 of the second two-way clutch 140 receives the same rotational force as that of the turbine shaft 106, and FIG. The posture is changed as shown in (B). Then, the idling direction of the turbine shaft 106 becomes an arrow Tccw, and the second two-way clutch 140 rotates clockwise with the turbine shaft 106, that is, rotates in the same direction as the input shaft 102.

  Here, in the forward D state, the stator brake mechanism SBR is in the engaged state and the rotation of the stator shaft 110 is stopped, while the turbine brake mechanism TBR is in the brake inoperative state, and the turbine shaft 106 is the same as the input shaft 102. Since the rotation is in the direction, a forward range in which the output shaft 120 rotates forward in the same direction as the turbine shaft 106 is formed as shown in FIG. The rotation directions of the output shaft 120 and the turbine shaft 106 at this time are indicated by arrows PScw and Tcw in FIGS. 4A, 4B, and 4C, respectively.

  Next, the reverse R state will be described with reference to FIG. During the reverse R, as described above, the brake operation of the stator brake mechanism SBR is disabled, and the hydraulic pressure is applied to the hydraulic actuator of the turbine brake mechanism TBR to perform the brake operation. When the stator brake mechanism SBR is not braked, the link member 160 connected to the piston 116 is moved in the axial direction (left direction in the figure) as shown in FIG. The annular first support plate 122 fixed to the outer diameter side of the output shaft 120 is moved together with the output shaft 120 in the axial direction (left direction in the drawing) via the fork 162. As a result, the pressing of the annular first pressing plate 152 to the scrub 132 is released, and at the same time, the pressing plate 124 fixed on the inner diameter side of the output shaft 120 is also moved in the axial direction (left direction in the drawing). The pressing of the second pressing plate 158 to the second sprag 142 is released.

  When the pressing of the first pressing plate 152 to the first scrub 132 and the pressing of the second pressing plate 158 to the second sprag 142 are released, both the stator shaft 110 and the turbine shaft 106 are As shown in FIG. 5B, the output shaft 120 can idle in the clockwise direction (as viewed by the arrow A in FIG. 5A). In FIG. 5B, the idling direction of the stator shaft 110 is indicated by an arrow Scw, and the idling possible direction of the turbine shaft 106 is indicated by an arrow Tcw.

  Therefore, if the direction of torque input from the engine ENG to the pump impeller 104 of the torque converter via the input shaft 102 is clockwise as indicated by an arrow Pcw in FIG. 5A, the turbine runner 108 or the turbine Since the rotation of the shaft 106 is blocked, the stator 114 receives a reaction force, rotates counterclockwise, and the stator shaft 110 connected to the stator 114 via the one-way clutch 112 also has an arrow in FIG. Rotate counterclockwise as indicated by Sccw.

  Here, in the reverse R state, the stator brake mechanism SBR is not operated and the brake is operated by applying hydraulic pressure to the hydraulic actuator of the turbine brake mechanism TBR, so that the stator shaft 110 rotates counterclockwise, that is, input. Since the rotation of the turbine shaft 106 is stopped while the turbine shaft 106 is rotating in the opposite direction, the output shaft 120 is stopped in a state where the turbine shaft 106 is stopped as shown in FIG. A reverse range is formed that rotates negatively in the same direction as the stator shaft 110. The rotation directions of the output shaft 120 and the stator shaft 110 at this time are indicated by arrows PSccw and Sccw in FIGS. 5A and 5C, respectively.

  Further, the neutral N state will be described with reference to FIG. In the present embodiment, at the neutral N time, both the stator brake mechanism SBR and the turbine brake mechanism TBR are set to the brake inoperative state. When the brake operation of the stator brake mechanism SBR is disabled, as shown in FIG. 6A, the link member 160 connected to the piston 116 is moved in the axial direction (the left direction in the figure) as in the case of reverse R. The annular first support plate 122 fixed to the outer diameter side of the output shaft 120 is moved in the axial direction (left direction in the figure) together with the output shaft 120 via the fork 162 provided at the tip portion. Will be. As a result, the pressing of the annular first pressing plate 152 to the scrub 132 is released, and at the same time, the pressing plate 124 that is a pressing member fixed to the inner diameter side of the output shaft 120 is also axially moved (the left direction in the drawing). ) And the pressing of the second pressing plate 158 to the second sprag 142 is released.

  When the pressing of the first pressing plate 152 to the first scrub 132 and the pressing of the second pressing plate 158 to the second sprag 132 are released, both the stator shaft 110 and the turbine shaft 106 are output. As shown in FIG. 6B, the shaft 120 can idle in the clockwise direction (viewed by an arrow A in FIG. 6A). In FIG. 6B, the idling direction of the stator shaft 110 is indicated by an arrow Scw, and the idling possible direction of the turbine shaft 106 is indicated by an arrow Tcw.

  Therefore, if the direction of torque input from the engine ENG to the pump impeller 104 of the torque converter via the input shaft 102 is clockwise as indicated by an arrow Pcw in FIG. 6A, the turbine runner 108 or the turbine The shaft 106 has the turbine brake mechanism TBR not braked, so the turbine runner 108 or the turbine shaft 106 is rotated in the same clockwise direction as the pump impeller 104. On the other hand, the stator 114 is also rotated clockwise, but the stator shaft 110 connected thereto via the one-way clutch 112 does not rotate. Therefore, as shown in FIG. 6C, even if the turbine shaft 106 rotates, the turbine shaft 106 only rotates idly, and no driving force is transmitted to the output shaft 120, so that a neutral range is formed.

  In the above-described embodiment, the stator brake mechanism SBR is braked during forward D and the turbine brake mechanism TBR is not braked, and the stator brake mechanism SBR is not braked during reverse R and the turbine brake mechanism. In order to obtain the neutral N state when the TBR is braked, both the stator brake mechanism SBR and the turbine brake mechanism TBR are braked. In this embodiment, since it is not necessary to supply hydraulic pressure to the stator brake mechanism SBR and the turbine brake mechanism TBR, for example, an effect of reducing the load of a control hydraulic pressure supply system such as an oil pump can be achieved.

  By the way, as another embodiment instead of the above-described embodiment, the neutral N state may be obtained by performing a braking operation on both the stator brake mechanism SBR and the turbine brake mechanism TBR. In this case, since both the stator brake mechanism SBR and the turbine brake mechanism TBR are braked, both the stator shaft 110 and the turbine shaft 106 do not rotate, and no power is transmitted to the output shaft 120 so that a neutral range is formed. It is done. According to this embodiment, at the time of switching from the neutral N to the forward D range, only the turbine brake mechanism TBR has to be braked, so that switching control is easy and smooth switching control without shock is performed. Is possible.

  In the above description, the embodiment in which the forward / reverse switching mechanism according to the present invention is applied to the CVT has been described.

It is a skeleton figure which shows embodiment which applied the forward / reverse switching mechanism by this invention to CVT. It is a schematic diagram of the 1st and 2nd two-way clutch for demonstrating the function of the forward / reverse switching mechanism by this invention, and shows the relationship with a turbine shaft, an output shaft, and a stator shaft. It is a flowchart which shows an example of the control procedure at the time of forward, reverse, and neutral switching in the forward / reverse switching mechanism according to the present invention. It is a figure for demonstrating the action | operation at the time of the forward movement in the forward / reverse switching mechanism by this invention, (A) is a skeleton figure which shows the state at the time of forward movement of the forward / backward switching mechanism, (B) is the 1st and 2nd FIG. 4C is a schematic diagram showing the state of the two-way clutch, and FIG. 6C is a schematic diagram showing the rotation directions of the turbine shaft, the output shaft, and the stator shaft. It is a figure for demonstrating the operation | movement at the time of reverse drive by the forward / reverse switching mechanism by this invention, (A) is a skeleton figure which shows the state at the time of reverse drive of a forward / reverse switching mechanism, (B) is 1st and 2nd FIG. 4C is a schematic diagram showing the state of the two-way clutch, and FIG. 6C is a schematic diagram showing the rotation directions of the turbine shaft, the output shaft, and the stator shaft. It is a figure for demonstrating the operation | movement at the time of neutral in the forward / reverse switching mechanism by this invention, (A) is a skeleton figure which shows the state at the time of neutral of the forward / backward switching mechanism, (B) is the 1st and 2nd FIG. 4C is a schematic diagram showing the state of the two-way clutch, and FIG. 6C is a schematic diagram showing the rotation directions of the turbine shaft, the output shaft, and the stator shaft.

Explanation of symbols

CVT belt type continuously variable transmission ENG engine SBR stator brake mechanism TBR turbine brake mechanism 100 forward / reverse switching mechanism 102 input shaft 104 pump impeller 106 turbine shaft 108 turbine runner 110 stator shaft 112 one-way clutch 114 stator 115 torque converter (fluid transmission mechanism)
116 Piston 120 Output shaft 122 First support plate 124 Press plate 130 First two-way clutch 132 First sprag 140 Second two-way clutch 142 Second sprag 150 First spring 152 First press plate 154 Second Support plate 156 Second spring 158 Second pressing plate 160 Link member 162 Fork 200 Electronic control unit (ECU)

Claims (5)

A pump impeller connected to the input shaft;
A turbine runner connectable to a turbine brake mechanism via a turbine shaft;
A fluid transmission mechanism having a stator connectable to a stator brake mechanism via a stator shaft; an output shaft disposed between the turbine shaft and the stator shaft; and disposed between the output shaft and the stator shaft A forward / reverse switching mechanism, comprising: a first two-way clutch that is arranged, and a second two-way clutch that is disposed between the output shaft and the turbine shaft.   The first and second two-way clutches operate so that the turbine shaft and the stator shaft do not rotate in the same direction as the input shaft with respect to the output shaft during a braking operation of the stator brake mechanism, and the turbine brake The forward / reverse travel according to claim 1, wherein the turbine shaft and the stator shaft are configured to operate so as not to rotate in a direction opposite to the input shaft with respect to the output shaft during a brake operation of the mechanism. Switching mechanism.   When the vehicle is moving forward, the stator brake mechanism is braked and the turbine brake mechanism is not operated. When the vehicle is moved backward, the stator brake mechanism is not operated and the turbine brake mechanism is braked. When the vehicle is neutral, the stator brake is operated. The forward / reverse switching mechanism according to claim 1 or 2, wherein both the brake mechanism and the turbine brake mechanism are inoperative.   When the vehicle is moving forward, the stator brake mechanism is braked and the turbine brake mechanism is not operated. When the vehicle is moved backward, the stator brake mechanism is not operated and the turbine brake mechanism is braked. When the vehicle is neutral, the stator brake is operated. The forward / reverse switching mechanism according to claim 1, wherein both the brake mechanism and the turbine brake mechanism are braked. The forward / reverse switching mechanism according to any one of claims 1 to 4, wherein the output shaft is spline-fitted to an input shaft of a belt type continuously variable transmission so as to be movable in the axial direction.

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