JPH0323406Y2 - - Google Patents

Description

[Detailed description of the invention] (Field of industrial application) The invention is an automatic transmission in which a lock pawl is engaged with a parking lock gear through a parking lock cam device by operating a control lever to lock an output shaft. Regarding the parking mechanism.

(Prior Art) A conventional parking mechanism of this type, as shown in Japanese Patent Publication No. 49-47378, has a lock pawl that engages with a parking lock gear, which is swingably supported on a mission case, and , fixing a cam support in the mission case at a position facing the lock pawl, and intervening between the lock pawl and the cam support a parking lock cam that is interlocked with a control lever disposed on the mission case; The lock pawl is swung toward the parking lock gear so that the lock pawl meshes with the parking lock gear.

(Problem to be Solved by the Invention) However, in the above parking mechanism, since the lock pawl is swingably supported by the mission case, the lock pawl is not provided within the mission case. Needless to say, sufficient space must be secured to allow the swinging of the locking claw, and a pivot for supporting the locking claw must be separately assembled to the mission case. Since the trajectory draws an arc, in order to ensure that the lock pawl engages with the parking lock gear, the length from the pivot point of the lock pawl to the site where it engages with the lock gear must be sufficiently long. In addition, the pivot position of the lock pawl relative to the mission case is also limited, resulting in a problem that the degree of freedom in design as a whole is reduced.

An object of the present invention is to provide a parking mechanism for an automatic transmission that is compact and can be easily and freely assembled into a transmission case.

(Means for Solving the Problems) Therefore, the present invention includes a parking lock cam device having a cam rod interlocked with a control lever and a cam body movably supported on the cam rod. , a parking mechanism for an automatic transmission in which a lock pawl is engaged with a parking lock gear via the parking lock cam device to lock the output shaft, the parking mechanism having a transmission case with approximately the diameter of the parking lock gear; An insertion hole extending in the direction of the parking lock is formed, and a pawl body that engages with the parking lock gear is integrally formed in the lock pawl, and the lock pawl is inserted into the insertion hole so as to be freely movable in a straight line. A return spring is interposed on the outer periphery of the pawl to bias the lock pawl outward in the radial direction of the parking lock gear, and a cam support facing the lock pawl is attached to the transmission case. One lengthwise end of the cam rod is interposed between the cam support and the lock pawl, and a spring is provided on the outer periphery of the cam rod to urge the cam body toward the lock pawl. That is.

(Function) According to the present invention, the insertion hole for the lock pawl is formed in the transmission case, and the cam support is attached to the transmission case, so the number of parts is reduced overall. It is possible to reliably and firmly lock the output shaft of an automatic transmission, and since the components of the return spring and parking lock cam are efficiently arranged around the periphery of the lock pawl, the entire mechanism can be housed compactly. It will be done.

(Example) Hereinafter, an example of the parking mechanism for an automatic transmission according to the present invention will be described based on the drawings.

The automatic transmission schematically shown in FIG. 4 includes a torque converter 2 in a transmission case 1.
, a clutch group 3 having a plurality of clutches that operate during gear shifting, and a planetary gear group 4 having a plurality of gears.
are arranged in series in the axial direction, and the reduction mechanism 5 is arranged parallel to the planetary gear group 4, so that the output gear 41 of the planetary gear group 4 meshes with the first reduction gear 51 of the reduction mechanism 5. A parking lock gear 6 is integrally formed with the first reduction gear 51 of the reduction mechanism 5, and by blocking the rotation of the parking lock gear 6, the driving force from the automatic transmission is reduced. a transmitted driveshaft 50,
It's like locking 50.

Next, a parking mechanism that prevents rotation of the parking lock gear 6 when the automatic transmission is switched to the parking range will be explained.

The parking mechanism shown in FIGS. 1 and 2 basically consists of a lock pawl 7 that meshes with the parking lock gear 6, and a lock pawl 7 that is locked by operating a control lever (not shown) disposed inside the vehicle. and a parking lock cam device 8 which meshes with the parking lock gear 6.

The lock claw 7 has a claw body 71 that engages between the teeth 61, 61 of the parking lock gear 6 at one end in the axial direction, and a truncated conical guide part 72 at the other end in the axial direction. The lock pawl 7 supports the transmission case 1 so as to be freely movable substantially linearly in the radial direction of the parking lock gear 6.

Specifically, a cylindrical insertion hole 11 extending in the radial direction of the parking lock gear 6 is formed in the transmission case 1 at a position facing the teeth 61 of the parking lock gear 6. The lock pawl 7 is inserted freely through the lock pawl 7, and a return spring 73 is interposed between the guide portion 72 of the lock pawl 7 and the mission case, and the repulsive force of the spring 73 is used to constantly The lock pawl 7 is urged in a direction away from the parking lock gear 6.

The parking lock cam device 8 includes a truncated conical cam body 81 that presses the lock pawl 7, a cam rod 82 that supports the cam body 81, and a cam rod 82 that freely swings on the mission case 1 via a shaft 83. A swinging arm 84 is supported by a swing arm 84 and has one end of the cam rod 82 connected to its free end, and a cam support 85 guides the cam body 81. The cam support 85 is fixed with bolts at a position facing the portion 72.

Then, the cam body 81 is attached to the cam rod 82.
A pair of locking pins 82a, 8 attached to both ends of
A spring 86 is interposed between the back surface of the cam body 81 and a locking pin 82b provided on the base side of the cam rod 82, and the repulsive force of the spring 86 causes the The cam body 81 is biased toward the free end of the cam rod 82, and the swing arm 84 swings clockwise in FIG. The cam body 8 is inserted between the guide portion 72 and the cam support 85.
1, the lock pawl 7 is moved in the axial direction against the return spring 73, and the pawl body 7 is moved.
1 is the tooth portion 61, 6 of the parking lock gear 6.
It is made so that it meshes between the two.

In the figure, 87 is a connecting arm whose one end is connected to the swinging arm 84 and the other end is operatively connected to a control lever (not shown) disposed inside the vehicle; 9 is a connecting arm when the swinging arm 84 swings; A detent device for regulating the swinging position of the swinging arm 84 is shown.

Next, the operation of the parking mechanism of the automatic transmission constructed as above will be explained.

By switching the control lever located in the vehicle compartment to the parking position, the swing arm 84
swings in the clockwise direction in FIG. It goes in between.

As shown in FIG. 3, as the lock pawl 7 enters between the guide portion 72 and the cam support 85, the cam body 81 is guided by the cam support 85 and faces the cam support 85. The lock pawl 7 is connected to the parking lock gear 6.
, so that the pawl body 71 of the cam lock pawl 7 touches the tooth portion 6 of the parking lock gear 6.
1 and 61, and the cam parking lock gear 6 and the drive shafts 50 and 50 are locked.

By the way, as described above, the cam body 81 is connected to the guide portion 72 of the lock pawl 7 and the cam support 8.
5, and the pawl body 71 of the cam lock pawl 7 is inserted between the teeth 61 and 5 of the parking cam gear 6.
61, the tooth tip of the tooth portion 61 of the parking lock gear 6 is in a position facing the pawl body 71 of the lock pawl 7, and the pawl body 71 engages the tooth portion 61 of the parking lock gear 6. ，
61, the cam body 81 does not forcefully enter between the guide portion 72 of the lock pawl 7 and the cam support 85, and only the cam rod 82 moves and the spring 86
From this state, the parking lock gear 6 rotates slightly and when the teeth 61, 61 of the parking lock gear 6 face the pawl body 71 of the lock pawl 7, the spring 86 repulses. The cam body 81 moves due to the force, and the lock pawl 7
is moved toward the parking lock gear 6, and as a result, the pawl body 71 of the lock pawl 7 engages between the teeth of the parking lock gear 6, and the parking lock gear 6 is locked.

(Effects of the invention) As described above, the parking mechanism for an automatic transmission according to the invention includes a parking lock cam device having a cam rod interlocked with a control lever and a cam body movably supported by the cam rod.
The parking mechanism for an automatic transmission is configured to lock an output shaft by engaging a lock pawl with a parking lock gear via the parking lock cam device by operating the control lever, An insertion hole extending substantially in the radial direction of the parking lock gear is formed, and a pawl body that engages with the parking lock gear is integrally formed in the lock pawl, so that the lock pawl can move linearly into the insertion hole. A return spring that is inserted into the transmission case and biases the lock pawl outward in the radial direction of the parking lock gear is interposed on the outer periphery of the lock pawl, while a cam that opposes the lock pawl is installed in the transmission case. A support is attached, one longitudinal end of the cam rod is interposed between the cam support and the lock pawl, and a spring is provided on the outer periphery of the cam rod to urge the cam body toward the lock pawl. By interposing the lock pawl, it goes without saying that there is no need for a pivot for supporting the lock pawl, which is required when the lock pawl is freely supported on the transmission case. Since a lock pawl insertion hole is formed and the cam support is attached to the transmission case, the output shaft of the automatic transmission can be reliably and firmly locked with fewer parts overall. Moreover, since the components of the return spring and parking lock cam are efficiently arranged around the periphery of the lock pawl, the entire mechanism can be made compact.

[Brief explanation of drawings]

The drawings show an embodiment of the parking mechanism for an automatic transmission according to the present invention, FIGS. 1 and 2 are sectional views thereof, and FIG. 3 is a sectional view corresponding to FIG. 1 showing the operating state of the parking mechanism. 4 are skeleton diagrams showing an embodiment of an automatic transmission to which the parking mechanism according to the present invention is applied. 1... Transmission case, 6... Parking lock gear, 7... Lock pawl, 8... Parking lock cam device.

Claims (1)

[Scope of utility model registration request] The parking lock cam device includes a cam rod interlocked with a control lever and a cam body movably supported by the cam rod, and when the control lever is operated, a lock pawl is engaged with a parking lock gear via the parking lock cam device. The parking mechanism for an automatic transmission is configured to lock an output shaft by locking the parking lock gear. A pawl body that engages with the lock gear is integrally formed, and the lock pawl is inserted into the insertion hole in a linear manner so as to be freely movable, and the lock pawl is attached to the outer periphery of the lock pawl so that the lock pawl is inserted radially outward of the parking lock gear. A return spring is interposed to bias the transmission case in the opposite direction, and a cam support facing the lock pawl is attached to the transmission case, and between the cam support and the lock pawl,
A parking mechanism for an automatic transmission, characterized in that a spring is interposed at one longitudinal end of the cam rod, and a spring is interposed on the outer periphery of the cam rod to urge the cam body toward the lock pawl.