WO2022196250A1

WO2022196250A1 - Shift-stage switching device

Info

Publication number: WO2022196250A1
Application number: PCT/JP2022/006744
Authority: WO
Inventors: 大蔵荻野; 均竹内; 周平大橋; 峻征川口; 広大山本
Original assignee: 三菱自動車工業株式会社
Priority date: 2021-03-18
Filing date: 2022-02-18
Publication date: 2022-09-22
Also published as: JP2024065133A

Abstract

When there is a command to mesh an inner peripheral gear (1604) of a sleeve (16) and a first gear (20A) or a second gear (20B), a shift-stage switching device (10) moves a shift fork (18) toward a meshing-command-side gear from a meshing completion position Px, which is the position on a fixed shaft (2208) where the sleeve (16) abuts on a stopper (2010B) of the meshing-command-side gear, and then returns the shift fork (18) to at least the meshing completion position (Px) and there puts the shift fork (18) into standby.

Description

gear shift device

The present invention relates to a gear changeover device for switching gears of a vehicle.

Conventionally, a gear shift device employed in a two-speed transaxle moves a shift fork holding a sleeve by an electric actuator to engage the inner peripheral spline of the sleeve with a gear piece spline of an arbitrary transmission gear. It adopts a dog clutch mechanism that shifts gears by

For example, Patent Literature 1 below describes a technique for accurately performing a reference value test (so-called "hitting learning") for testing a reference value of a signal indicating a shift range in a shift range switching device mounted on a vehicle. disclosed. In the abutting learning of the shift range switching device in Patent Document 1, the driven body is abutted against the stopper so as to bend one or both of the driven body and the stopper, and the amount of current is reduced while the DC motor is kept energized in all phases. By reducing the deflection, the deflection is reduced, and the value of the position signal from the encoder when it is detected that the deflection has disappeared is used as the reference value. Therefore, since the reference value is determined in a state in which the deflection is eliminated, variations in the reference value caused by the deflection do not occur. That is, since the reference value does not fluctuate even when conditions such as temperature change, it is possible to switch the shift range with high accuracy.

Japanese Patent No. 6443189

In the conventional gear shift device (meshing clutch mechanism), after the sleeve has been completely engaged with the desired gear piece, in order to ensure the engagement, the sleeve is pressed against the stopper with a predetermined load in the direction of the gear, and then transferred to the electric actuator. Shifting is completed by cutting off the current supply to the
Further, the electric actuator of the conventional speed changer adopts a configuration in which a ball screw is inserted into a DC brushless motor. The ball screw has a high reverse rotation efficiency, and if the current supply to the electric actuator is cut off, the holding force of the sleeve is lost. The position of the shift fork and sleeve is fixed at the specified position by the retracting force of the sublock mechanism (detent).
On the other hand, if a slide screw or other mechanism with low reverse rotation efficiency is used for the electric actuator of the gear shift device, the holding force remains even if the current supply to the electric motor is cut off, and there is no sublock mechanism (detent). However, the shift fork and sleeve positions are retained. However, as in the conventional switching device, when the sleeve is pressed against the stopper with a predetermined load in the direction of the gear after the engagement with the desired gear piece is completed, and the current supply to the electric actuator is cut off, pressing due to deflection of the shift fork or the like may occur. power remains. This pressing force may cause problems such as melting the fork pad of the shift fork.

In addition, in Patent Document 1 mentioned above, there is a problem that a sensor for detecting the amount of deflection of the driven body or the stopper with high accuracy is required, which increases the cost. Moreover, in Patent Document 1 described above, the driven body is operated while reading the motor current value, and there is a problem that the operation is complicated.

The present invention has been made in view of such circumstances, and its object is to suppress the wear of the members constituting the gear change device while ensuring the change of the gear of the vehicle.

In order to achieve the above object, one embodiment of the present invention is a gear shift device for switching gear stages of a vehicle, comprising a clutch hub provided on a drive shaft and an inner spline meshing with the clutch hub. a shift fork that rotatably supports the sleeve; a first gear that is rotatably disposed at the drive shaft on both sides of the clutch hub and has outer splines that can mesh with the inner splines; The shift fork is moved on a fixed shaft along the center line of the drive shaft using a second gear, a stopper provided on the first gear and the second gear and capable of coming into contact with the sleeve, and an electric motor. a moving mechanism for selectively meshing the inner peripheral spline with the outer peripheral spline of the first gear and the outer peripheral spline of the second gear by moving a stroke for detecting the position of the shift fork on the fixed shaft; a sensor, and a movement control section that controls the movement state of the shift fork based on the detection value of the stroke sensor, wherein the movement control section controls the movement of the inner spline and the first gear or the second gear. , the shift fork is moved from a meshing completion position, which is a position on the fixed shaft where the sleeve abuts against the stopper of the meshing command side gear, to the meshing command side gear side, and then at least the meshing completion It is characterized in that the shift fork is returned to the position and made to stand by.

According to one embodiment of the present invention, when a gear change command to a predetermined gear is given, the sleeve abuts against the stopper of the gear on the switching side (engagement command side gear), and the fixed shaft does not deform the shift fork. After the shift fork is moved from the engagement completion position, which is the upper position, toward the switching side gear, and the engagement between the gears is completed while the shift fork is deformed, the shift fork is returned to at least the engagement completion position and waited. . As a result, the pressing of the sleeve against the stopper by the shift fork is released, and abrasion of the fork pad of the shift fork and abrasion of the contact surface between the sleeve and the stopper can be prevented.

1 is a cross-sectional perspective view showing an overall configuration of a gear shift device according to an embodiment; FIG. FIG. 2 is a view showing the configuration of a shift fork moving mechanism from the rear side of FIG. 1; FIG. 4 is a cross-sectional view schematically showing the meshing relationship of gears that constitute the gear shift device; It is a figure which shows typically the engagement relationship of each gear which comprises a gear stage switching apparatus. 2 is a cross-sectional view schematically showing the configuration of an electric actuator; FIG. FIG. 4 is an explanatory diagram schematically showing movement of a shift fork, showing a case where the shift fork is at a reference position; FIG. 4 is an explanatory view schematically showing movement of a shift fork, showing a case where the shift fork is at the movement limit position and is bent. FIG. 4 is an explanatory diagram schematically showing movement of a shift fork, showing a case where the shift fork is in a meshing completion position; FIG. 4 is an explanatory diagram schematically showing movement of a shift fork, showing a case where the shift fork is in a standby position; 4 is a timing chart showing changes over time in the position of the shift fork (detected value of the stroke sensor) and the current value of the electric motor; 4 is a flow chart showing a procedure of learning processing of an engagement completion position by a movement control unit;

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of a gear shift device and a control method for the gear shift device according to the present invention will be described below in detail with reference to the accompanying drawings.
A configuration of a gear shift device 10 according to an embodiment will be described with reference to FIGS. 1 to 6. FIG.
A gear shift device 10 switches gear stages of a vehicle of an automatic transmission between two stages of a high (H) gear and a low (L) gear. It includes a first gear 20A, a second gear 20B, a moving mechanism 22, a stroke sensor 24, and a movement control section 300 (see FIG. 6).

The drive shaft 12 is an output shaft that transmits engine power to the drive wheels of the vehicle.

The clutch hub 14 is provided on the drive shaft 12 and has an outer peripheral spline 1402 on its outer peripheral portion as shown in FIG. Clutch hub 14 and drive shaft 12 are spline-connected, whereby clutch hub 14 rotates together with drive shaft 12 .

The sleeve 16 is a cylindrical member having an inner spline 1604 that meshes with the outer spline 1402 of the clutch hub 14 . More specifically, as shown in FIG. 3, the sleeve 16 has a cylindrical sleeve base portion 1602 provided with an inner peripheral spline 1604, and a shift fork 18 provided on the outer peripheral portion of the sleeve base portion 1602, which can be engaged. and an engaging portion 1606 . The engaging portion 1606 includes an outer peripheral surface 1608 of the sleeve base portion 1602 and ridges 1610 on both sides of the outer peripheral surface 1608 in a direction orthogonal to the circumferential direction.

A shift fork 18 rotatably supports the sleeve 16 . The shift fork 18 is movable in the extension direction of the drive shaft 12 by a movement mechanism 22 which will be described later. As the shift fork 18 moves, the sleeve 16 also moves in the extension direction of the drive shaft 12 .
As shown in FIG. 2, the shift fork 18 includes a holding portion 1802 that holds the sleeve 16, a tubular portion 1804 through which a fixed shaft 2208 of the moving mechanism 22 (to be described later) is inserted, the holding portion 1802 and the tubular portion 1804. and a main body portion 1806 for connecting the .
The holding portion 1802 has a contact surface 1808 that rotatably contacts the outer peripheral surface 1608 between the ridges 1610 provided on the outer peripheral portion of the sleeve 16 as shown in FIG. Further, as shown in FIG. 2, a fork pad 1812 is attached to a side wall 1810 of the holding portion 1802 that faces the ridge 1610 in order to prevent seizure when the shift fork 18 contacts the sleeve 16 with relative rotation. It is
As shown in FIG. 3, the width (including the thickness of the fork pad 1812) W1 of the contact surface 1808 of the holding portion 1802 in the direction orthogonal to the circumferential direction of the outer peripheral surface 1608 of the sleeve 16 is It is smaller than the dimension W2 between them. That is, a gap (play) of distance W2-W1 is provided between the holding portion 1802 of the shift fork 18 and the engaging portion 1606 of the sleeve 16. As shown in FIG.

The first gear 20A and the second gear 20B are rotatably arranged at the drive shaft 12 on both sides of the clutch hub 14 as shown in FIG. The first gear 20A corresponds to a high gear, and an outer peripheral gear 2008A of a large diameter portion 2004A, which will be described later, meshes with a third gear 34A fixed to the countershaft 32 indicated by a two-dot dashed line in FIG. The second gear 20B corresponds to a low gear, and an outer peripheral gear 2008B of a large diameter portion 2004 (to be described later) meshes with a fourth gear 34B fixed to the countershaft 32 to rotate.
The first gear 20A and the second gear 20B are connected to the drive shaft 12 via needle roller bearings (not shown), and the first gear 20A or the second gear 20B corresponds to the desired shift. By connecting the drive shaft 12 with the sleeve 16 via the clutch hub 14 , the rotation of the gear is transmitted to the drive shaft 12 . A position restricting member (not shown) is provided so that the axial positions of the first gear 20A and the second gear 20B do not change.

As shown in FIG. 3, the first gear 20A and the second gear 20B respectively have splines 2002 (2002A, 2002B) arranged adjacent to the clutch hub 14 and large splines 2002 (2002A, 2002B) arranged away from the clutch hub 14. and a diameter portion 2004 (2004A, 2004B).
The splines 2002 of the first gear 20A and the second gear 20B have outer splines 2006 (2006A, 2006B) that can mesh with the inner splines 1604 of the sleeve 16, respectively.
The large diameter portion 2004 has a larger radius than the spline 2002, and the outer peripheral gear 2008 (2008A, 2008B) provided on the outer periphery of the large diameter portion 2004 is the outer peripheral gear 3400A of the third gear 34A fixed to the countershaft 32 or the fourth gear. 34B are in constant mesh with the outer peripheral gear 3400B.

The moving mechanism 22 uses an electric motor 2204A to move the shift fork 18 along the centerline O of the drive shaft 12, thereby moving the inner spline 1604 of the sleeve 16 to the outer spline 2006A of the first gear 20A and the outer spline 2006A of the second gear 20B. is selectively engaged with the outer peripheral spline 2006B.
In this embodiment, the moving mechanism 22 includes an electric actuator 2204, a moving shaft 2206, a guide portion 2210, and a lever 2212, as shown in FIG. Guide portion 2210 and shift fork 18 are provided integrally.
As shown in FIG. 5, the electric actuator 2204 has an electric motor (in this embodiment, a DC brush motor) 2204A with a slide screw 2204B inserted therein. It functions as a linear motion mechanism that converts to linear motion. The electric motor 2204A rotates the female screw side of the slide screw 2204B, thereby moving the electric actuator 2204 vertically (in the direction of arrow A in FIG. 2). That is, the moving mechanism 22 moves the shift fork 18 by converting the rotational force output by the electric motor 2204A into a moving force in the linear motion direction by the slide screw 2204B connected to the output shaft of the electric motor 2204A.
The moving shaft 2206 is attached to the tip of the output shaft 2204C of the electric actuator 2204, and moves along with the movement of the electric actuator 2204 in the linear motion direction (arrow A direction in FIG. 2).
The guide portion 2210 is integrated with the shift fork 18 as described above, and includes a body portion 2210A, an insertion hole 2210B through which a lever 2212 (to be described later) is inserted, and a spring 2210C through which the fixed shaft 2208 is inserted.
Lever 2212 has a substantially L-shape, one end 2212A is inserted into connecting portion 2206A provided on moving shaft 2206, and the other end 2212B is inserted through insertion hole 2210B of guide portion 2210. As shown in FIG. Lever 2212 can swing around a support shaft 2212C supported by the vehicle body.
When the electric actuator 2204 operates and the moving shaft 2206 moves vertically (in the direction of arrow A), the lever 2212 swings and the shift fork 18 and the guide portion 2210 perform reciprocating linear motion (in the direction of arrow B).

The stroke sensor 24 detects the position of the shift fork 18 by reading the motion of the guide portion 2210 . In the present embodiment, the stroke sensor 24 detects the position of the shift fork 18 when the axial center position of the holding portion 1802 of the shift fork 18 is positioned at the axial center position S0 of the clutch hub 14 (see FIG. 3). is defined as a reference position P0, and the position of the shift fork 18 is detected by detecting the amount of movement of the shift fork 18 from this reference position P0.
That is, the stroke sensor 24 measures the movement distance of the shift fork 18 from the reference position P0 of the shift fork 18 where the inner spline 1604 of the sleeve 16 does not mesh with the outer spline 2006A of the first gear 20A and the outer spline 2006B of the second gear 20B. to detect

As shown in FIG. 3, when the sleeve 16 is positioned on the outer circumference of the clutch hub 14, neither the first gear 20A nor the second gear 20B are connected to the drive shaft 12 and rotate around the drive shaft 12 respectively. rotating independently. In this case, the gear stage of the vehicle becomes neutral (N).
On the other hand, as shown in FIG. 4, when the sleeve 16 is moved in the direction of the first gear 20A by the shift fork 18, a part of the inner peripheral spline 1604 of the sleeve 16 and the outer peripheral spline 2006A of the spline 2002A of the first gear 20A mesh. do. The remaining part of the inner peripheral spline 1604 of the sleeve 16 meshes with the clutch hub 14, whereby the first gear 20A, the sleeve 16 and the clutch hub 14 are integrated, and the rotational force of the drive shaft 12 is transferred to the sleeve 16 and the clutch hub 14. It is transmitted to the countershaft 32 via the first gear 20A and the third gear 34A. When the sleeve 16 is engaged with the first gear 20A, the vehicle is in high gear.
Further, when the sleeve 16 is moved toward the second gear 20B by the shift fork 18, part of the inner peripheral spline 1604 of the sleeve 16 and the outer peripheral spline 2006B of the spline 2002B of the second gear 20B are meshed. The remaining part of the inner peripheral spline 1604 of the sleeve 16 is meshed with the clutch hub 14, whereby the second gear 20B, the sleeve 16 and the clutch hub 14 are integrated, and the rotational force of the drive shaft 12 is transferred to the sleeve 16 and the clutch hub 14. It is transmitted to the counter shaft 32 via the second gear 20B and the fourth gear 34B. When the sleeve 16 is engaged with the second gear 20B, the vehicle is in low gear.

As shown in FIG. 4, when the sleeve 16 is moved axially in the first gear 20A direction by the shift fork 18, the axial end surface 1612 of the sleeve 16 comes into contact with the side surface of the large diameter portion 2004 on the clutch hub 14 side. , restrict the axial movement of the sleeve 16 .
That is, in the present embodiment, the side surfaces of large-diameter portion 2004 function as stoppers 2010 (2010A, 2010B) provided on first gear 20A and second gear 20B and capable of contacting sleeve 16 .

Next, the movement control section 300 will be explained.
As shown in FIG. 6, the movement control unit 300 is implemented as one function of a TCU (Transmission Control Unit) 30 that controls the transmission of the vehicle.
The TCU 30 includes a CPU (Central Processing Unit), a ROM (Read Only Memory) for storing control programs and the like, a RAM (Random Access Memory) as an operating area for the control programs, and an EEPROM (Electrically Rewritable) for holding various data. (Erasable Programmable ROM), an interface unit for interfacing with peripheral circuits, etc., and the CPU functions as a movement control unit 300 by executing the control program.

The movement control section 300 controls the movement state of the shift fork 18 based on the detection value of the stroke sensor 24 . For example, when an ECU (Electronic Control Unit) that controls the entire vehicle issues a command to switch gears (i.e., when a command is issued to engage the sleeve 16 with the first gear 20A or the second gear 20B), the movement control unit 300 Electric actuator 2204 is operated to move shift fork 18 to a position where gear 20 and sleeve 16 corresponding to the gear are engaged.

In this embodiment, as shown in FIG. 8, the end surface 1612 of the sleeve 16 is in contact with the side surface (stopper 2010) of the large diameter portion 2004 of the gear 20, and the shift fork 18 is meshed at a position where deformation (deflection) does not occur. Assume that the completion position (stopper position) is Px.
Then, when there is a shift stage switching command (engagement command between the sleeve 16 and the predetermined gear 20), first, the gear on the side of the engagement command side from the engagement completion position Px (for example, the movement limit position Pl (see FIG. 7) described later). After the sleeve 16 and the gear 20 are reliably meshed by moving the shift fork 18 to and pressing the sleeve 16 against the gear 20, the shift fork 18 is returned at least to the meshing completion position Px, and then the next gear stage is set. Wait until switching command.
That is, the movement control unit 300 causes the sleeve 16 to abut against the stopper 2010 of the gear on the side of the engagement instruction and to the shift fork 18 when the inner spline 1604 of the sleeve 16 and the first gear 20A or the second gear 20B are instructed to engage. After the shift fork 18 is moved from the meshing completion position Px, which is a position on the fixed shaft 2208 where deformation does not occur, to the gear on the meshing instruction side, and after the shift fork is deformed, the shift fork 18 is returned to at least the meshing completion position Px. wait.

The engagement completion position Px is determined by learning of the movement control unit 300 rather than being specified in advance.
The reason why the engagement completion position Px is set in the gear shift device 10 according to the embodiment will be described.
As described above, the electric actuator of the conventional gear shift device employs a configuration in which a ball screw is inserted into a DC brushless motor. The ball screw has a high reverse rotation efficiency, and if the current supply to the electric actuator is cut off, the holding force of the sleeve is lost. The position of the shift fork and sleeve is fixed at the specified position by the retracting force of the sublock mechanism (detent).

On the other hand, when a mechanism having a low reverse rotation efficiency such as a slide screw 2204B is employed for the electric actuator 2204 of the gear shift device 10 according to the embodiment, the holding force remains even if the electric current supply to the electric motor 2204A is cut off. , the positions of the shift fork 18 and the sleeve are maintained even without a sublock mechanism (detent).
However, as in the conventional switching device, when the sleeve is pressed against the stopper with a predetermined load in the direction of the gear after the sleeve has been engaged with the desired gear piece, and the current supply to the electric actuator 2204 is interrupted, the shift fork 18 may be bent. The pressing force due to remains. This pressing force may cause problems such as melting the fork pad 1812 of the shift fork 18 .

For this reason, the gear shift device 10 completes shifting (turns off the electric actuator) in a state where the sleeve is pressed against the gear as in the conventional art. The position (engagement completion position) of contact with the side surface (stopper 2010) of the diameter portion 2004 is learned, and after returning the shift fork 18 to at least the engagement completion position, the shift engagement is completed.

The dimensions of the clutch hub 14, the sleeve 16, the first gear 20A, the second gear 20B, etc. are constant, and a method of determining the engagement completion position based on these dimensions (design values) may be considered. There is a possibility that mechanical errors in dimensions and variations in characteristics of the stroke sensor 24 may occur, and it is considered that a uniform value is insufficient to solve the above problems. conduct.

Details of learning by the movement control unit 300 will be described using the flowchart of FIG. 11 while referring to FIGS. 6 to 10. FIG.
6 to 9, illustration of the clutch hub 14, the stroke sensor 24, etc. is omitted from the viewpoint of visibility.
In the initial state, the shift fork 18 is assumed to be at the reference position P0 as shown in FIG.
When movement control unit 300 receives a movement amount learning instruction (step S900: Yes), movement control unit 300 operates electric actuator 2204 at a constant speed, and shifts shift fork 18 and sleeve 16 held by shift fork 18 in one gear direction ( 10A) at a constant speed (step S902, corresponding to times T0 to T1 in FIG. 10). The stroke sensor 24 detects the amount of movement (distance) of the shift fork 18 from the reference position P0.

When the inner peripheral spline 1604 of the sleeve 16 meshes with the outer peripheral spline 2006 of the spline 2002 of the first gear 20A and the axial end surface 1612 of the sleeve 16 reaches a position (stopper position) where it abuts against 2010A of the large diameter portion 2004, The moving speed of shift fork 18 decreases. The moving speed of the shift fork 18 can be calculated, for example, from the amount of change per unit time in the detection value of the stroke sensor 24 .
When the movement speed of the shift fork 18 decreases (step S904: Yes, corresponding to times T1 to T2 in FIG. 10), that is, when it detects that the sleeve 16 has reached the stopper position, the movement control unit 300 temporarily shifts the electric actuator 2204. is cut (step S906, corresponding to times T2 to T3 in FIG. 10).

Next, the movement control unit 300 applies a constant voltage to the electric actuator 2204 to further move the shift fork 18 and the sleeve 16 held by the shift fork 18 in the direction of the first gear 20A (step S908, time of FIG. 10). corresponding to T3-T4). That is, as shown in FIG. 7, the shift fork 18 is further moved so as to press the sleeve 16 toward the large diameter portion 2004 (toward the stopper). At this time, the shift fork 18 is flexed D due to the pressing force in the direction of the stopper. 7 schematically shows the deflection of the shift fork 18. As shown in FIG.

The movement control unit 300 continues pressing with a constant voltage until the detection value of the stroke sensor 24 (denoted as "stroke" in the figure) stabilizes (step S910: No). When the detection value of stroke sensor 24 stabilizes (step S910: Yes), movement control unit 300 determines that position to be the movement limit position of shift fork 18, and the detection value of stroke sensor 24 and electric actuator 2204 at that point in time. The value of the flowing current is read (step S912, corresponding to time T4 in FIG. 10).

Subsequently, the movement control unit 300 estimates the axial load that the shift fork 18 receives from the movement mechanism 22 based on the current value of the electric actuator 2204 obtained in step S912 (step S914). In general, the current value of the electric actuator 2204 is proportional to the load received from the shift fork 18, and the movement control unit 300 reads the load value corresponding to the current value from a map prepared in advance by actual measurement.

Further, the movement control unit 300 estimates the axial strain amount (corresponding to D in FIG. 7) occurring in the shift fork 18 based on the load obtained in step S914 (step S916). In general, the load applied to a member and the strain amount of the member are in a proportional relationship, and the movement control unit 300 reads the strain amount value corresponding to the load from a map prepared in advance by actual measurement.
Note that the map prepared in advance may be such that the strain amount of the shift fork 18 can be obtained directly from the current value in step S912.

Movement control unit 300 determines a value obtained by subtracting the strain value obtained in step S916 from the value detected by stroke sensor 24 when the stroke is stable, read in step S912, as engagement completion position Px (step S918). End the process.
Thereafter, the engagement completion position Px is similarly learned for the other gear direction (the second gear 20B direction in the above example).

That is, the movement control unit 300 drives the electric motor 2204A at a constant voltage, and the sleeve 16 contacts the stopper 2010 (side surface of the large-diameter portion 2004 of the gear 20) to restrict movement of the shift fork 18. When the shift fork 18 reaches the movement limit position Pl, the amount of deflection D of the shift fork 18 at the movement limit position Pl is estimated based on the current flowing through the electric motor 2204A when the shift fork 18 reaches the movement limit position. The position obtained by subtracting the amount of deflection D from the value detected by the stroke sensor 24 when reaching Pl is learned as the engagement completion position Px.

Learning of the engagement completion position by the movement control unit 300 is performed at least once, for example, before shipment of the vehicle. Further, the movement control unit 300 may perform learning of the engagement completion position at predetermined intervals after the start of use of the vehicle. This is because there is a possibility that the fork pad 1812 will be worn and the motion characteristics of each member of the moving mechanism 22 will change due to use over time.
The predetermined period may be set, for example, at predetermined time intervals (every three months, every year, etc.), or at predetermined travel distances (every 10,000 km travel distance, etc.).

As described above, the movement control unit 300 first moves the shift fork 18 to the movement limit position Pl (see FIG. 7) when there is a shift stage switching command (engagement command between the sleeve 16 and the predetermined gear 20). After the sleeve 16 and the gear 20 are reliably meshed by moving the sleeve 16 and pressing it against the gear 20, the shift fork 18 is returned to at least the meshing completion position Px, and then the power supply to the electric actuator 2204 is cut off, Standby until the next shift stage switching command. As a result, the pressing force applied to the sleeve 16 in the direction of the gear 20 (stopper) can be reduced to almost zero, and wear of the fork pad 1812 and deterioration of the shift fork 18 can be prevented.

On the other hand, when the shift fork 18 is at the engagement completion position Px, the fork pad 1812 on the side of the gear 20 is in contact with the ridge 1610 of the sleeve 16, and even a slight error in the amount of movement causes a pressing force against the sleeve 16. may be affected.
Therefore, in the present embodiment, the standby position of the fork pad 1812 after the completion of shifting is the position where the fork pad 1812 is in contact with the ridge 1610 of the sleeve 16 on the opposite side of the gear 20 (standby position), as shown in FIG. Py).
As shown in FIG. 9, the width (including the thickness of the fork pad 1812) W1 of the contact surface 1808 of the holding portion 1802 in the direction orthogonal to the circumferential direction of the outer peripheral surface 1608 of the sleeve 16 is It is smaller than the dimension W2 between them. That is, a gap (play) of distance W2-W1 is provided between the holding portion 1802 of the shift fork 18 and the engaging portion 1606 of the sleeve 16. As shown in FIG.
The standby position Py is a gap distance W2-W1 away from the engagement completion position Px on the side opposite to the gear 20 being engaged (toward the clutch hub 14).
That is, the movement control unit 300 stores the gap distance W2-W1 obtained by subtracting the width of the contact surface 1808 including the fork pad 1812 from the dimension W2 between the ridges 1610 on both sides of the sleeve 16, and stores the gap distance W2-W1 when the shift fork 18 is engaged. to the movement limit position Pl, the shift fork 18 may be made to wait at a position (standby position Py) separated from the engagement completion position Px in the direction opposite to the gear 20 by the gap distance W2-W1.
By doing so, the gear 20 and the sleeve 16 can be reliably meshed (shifted), and wear of each member constituting the gear shift device 10 can be prevented more reliably.

As described above, in the gear change device 10 according to the embodiment, when a shift change command to a predetermined shift is given, the sleeve 16 abuts against the stopper 2010 of the gear 20 on the changeover side (engagement command side gear), and The shift fork 18 is moved toward the gear 20 on the switching side from the engagement completion position Px, which is a position on the fixed shaft 2208 where the shift fork 18 is not deformed, and the engagement between the gears is completed while the shift fork 18 is deformed. After that, the shift fork 18 is returned to at least the engagement completion position and waited. As a result, the pressing of the sleeve 16 against the stopper 2010 by the shift fork 18 is released, and wear of the fork pad 1812 of the shift fork 18 and wear of the contact surface between the sleeve 16 and the stopper 2010 can be prevented. Further, by moving the shift fork 18 from the engagement completion position Px toward the gear 20 on the switching side, the inner spline 1604 of the sleeve 16 is brought into engagement with the gear 20 on the switching side, thereby securely completing the shift.
Further, in the gear shift device 10 according to the embodiment, the standby position until the next shift switching is set to a position (standby position Py) separated by a gap distance W2-W1 in the direction opposite to the gear 20 from the engagement completion position Px. By doing so, it is possible to more reliably prevent wear of each member constituting the gear shift device 10 .
Further, in the gear shift device 10 according to the embodiment, the shift fork 18 is moved to the movement limit position Pl, and when the shift fork 18 reaches the movement limit position Pl, the movement limit is determined based on the current flowing through the electric motor 2204A. If the deflection amount D of the shift fork 18 at the position Pl is estimated, and the position obtained by subtracting the deflection amount from the detection value of the stroke sensor when the shift fork 18 reaches the movement limit position Pl is learned as the engagement completion position Px, the shift The amount of deflection can be estimated without providing a sensor for detecting the amount of deflection of the fork 18, and the cost of the gear changeover device 10 can be reduced.
Further, in the gear shift device 10 according to the embodiment, if the slide screw 2204B is adopted as the rotation-linear motion conversion mechanism of the electric actuator 2204, the rotation-linear motion conversion can be performed in comparison with the conventional configuration using a ball screw or the like. The parts cost of the mechanism can be reduced. Further, by utilizing the fact that the reverse rotation efficiency of the slide screw is low, the sub-lock mechanism for holding the position of the shift fork can be eliminated, and further cost reduction can be realized.
Further, in the gear shift device 10 according to the embodiment, if the learning of the engagement completion position is executed at predetermined intervals after the start of use of the vehicle, the gear shift device 10 can be engaged in a state that reflects changes in each part of the gear shift device 10 due to long-term use. The completion position can be set, and wear of each member constituting the gear shift device 10 can be prevented more reliably.

Various embodiments have been described above with reference to the drawings, but it goes without saying that the present invention is not limited to such examples. It is obvious that a person skilled in the art can conceive of various modifications or modifications within the scope described in the claims, and these also belong to the technical scope of the present invention. Understood. Moreover, each component in the above embodiments may be combined arbitrarily without departing from the gist of the invention.

This application is based on a Japanese patent application (Japanese Patent Application No. 2021-044651) filed on March 18, 2021, the content of which is incorporated herein by reference.

REFERENCE SIGNS LIST 10 gear shift device 12 drive shaft 14 clutch hub 16 sleeve 1602 sleeve base 1604 inner spline 1606 engaging portion 1608 outer peripheral surface 1610 ridge 1612 end surface 18 shift fork 20A first gear 20B second gear 2002 (2002A, 2002B) spline 2004 (2004A, 2004B) Large diameter portion 2006 (2006A, 2006B) Peripheral spline 2008 (2008A, 2008B) Peripheral gear 2010 (2010A, 2010B) Stopper 22 Moving mechanism 2204 Electric actuator 2204A Electric motor 2204B Slide screw 2204C Output shaft movement 2 2208 Fixed shaft 2210 Guide part 2212 Lever 24 Stroke sensor 300 Movement control part 32 Counter shaft P0 Reference position Pl Movement limit position Px Engagement completion position Py Standby position

Claims

A gear stage switching device for switching gear stages of a vehicle,
a clutch hub provided on the drive shaft;
a sleeve having an inner peripheral spline that meshes with the clutch hub;
a shift fork that rotatably supports the sleeve;
a first gear and a second gear rotatably disposed at the drive shaft on both sides of the clutch hub and each having an outer spline meshable with the inner spline;
a stopper provided on the first gear and the second gear and capable of coming into contact with the sleeve;
By moving the shift fork on a fixed shaft along the center line of the drive shaft using an electric motor, the inner spline is aligned with the outer spline of the first gear and the outer spline of the second gear. a moving mechanism for selectively engaging;
a stroke sensor that detects the position of the shift fork on the fixed shaft;
a movement control unit that controls the movement state of the shift fork based on the detection value of the stroke sensor,
The movement control unit moves a mesh completion position, which is a position on the fixed shaft at which the sleeve abuts the stopper of the mesh command side gear, when a mesh command is issued between the inner peripheral spline and the first gear or the second gear. After moving the shift fork to the engagement command side gear side, the shift fork is returned to at least the engagement completion position and waited.
A gear stage switching device characterized by:
The sleeve has a cylindrical sleeve base portion provided with the inner peripheral spline, and an engaging portion provided on the outer peripheral portion of the sleeve base portion and capable of being engaged with the shift fork,
The engaging portion includes an outer peripheral surface of the sleeve base and ridges on both sides that stand up from both sides of the outer peripheral surface in a direction orthogonal to the circumferential direction,
The shift fork has a holding portion having a contact surface that rotatably contacts the outer peripheral surface between the ridges on both sides, and the width of the contact surface in a direction orthogonal to the circumferential direction of the outer peripheral surface is smaller than the dimension between the ridges on both sides,
The movement control unit stores a clearance distance obtained by subtracting the width of the contact surface from the dimension between the protrusions on both sides, and when the engagement command is issued, moves the shift fork from the engagement completion position to the gear on the engagement command side. After the shift fork is moved, the shift fork waits at a position separated by the gap distance in the direction opposite to the engagement command side gear from the engagement completion position.
2. The gear shift device according to claim 1, wherein:
The movement control unit drives the electric motor at a constant voltage to move the sleeve to a movement limit position where movement of the shift fork is restricted by pressing the sleeve against the stopper. The amount of deflection of the shift fork at the movement limit position is estimated based on the current flowing through the electric motor when the shift fork reaches the movement limit position, and from the detection value of the stroke sensor when the shift fork reaches the movement limit position. learning the position from which the deflection amount is subtracted as the engagement completion position;
3. The gear shift device according to claim 1 or 2, characterized in that:
The moving mechanism converts a rotational force output by the electric motor into a moving force in a linear motion direction by a slide screw connected to an output shaft of the electric motor to move the shift fork.
4. The gear changeover device according to any one of claims 1 to 3, characterized in that:
The movement control unit learns the engagement completion position every predetermined period after the vehicle starts to be used.
5. The gear changeover device according to any one of claims 1 to 4, characterized in that: