JPH11153201A - Continuously variable transmission - Google Patents

Abstract

PROBLEM TO BE SOLVED: To shorten an entire length of a continuously variable transmission and to reduce a manufacturing cost by simplifying a structure of the transmission for simplifying a molding structure. SOLUTION: A primary pulley of which a pulley groove width is variable is mounted on a primary shaft 21, and a secondary pulley of which a pulley groove width is variable and which is connected to the primary pulley through a metal belt layed therebetween is mounted on an output shaft. The primary pulley and the secondary pulley are stored in a case housing 22. A shaft side oil passage 35 is formed in the primary shaft 21 so as to open at an end surface which is at an opposite side of an engine. An opening 35a of the shaft side oil passage 35 faces an outer side of the case housing 22 in the condition of the primary shaft 21 being sealed with the case housing 22. A housing side oil passage 25 is formed at the case housing 22 and opens to an end surface 22a. A cover member having a space portion 27a covers the opening 35a of the shaft side oil passage 35 and an opening 25a of the housing side oil passage 25 and is mounted at the end surface 22a of the case housing 22.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a continuously variable transmission for a vehicle, and more particularly, to a structure of a circuit for supplying hydraulic pressure to a primary pulley of the continuously variable transmission.

[0002]

2. Description of the Related Art Generally, a continuously variable transmission for a vehicle generally has a continuously variable transmission mechanism which is a main transmission mechanism for continuously adjusting a gear ratio according to a running state, and a starting device for controlling power transmission from an engine. And a forward / reverse switching mechanism for changing the drive rotation direction of the continuously variable transmission mechanism in accordance with the forward and backward movement of the vehicle. FIG. 3 is a skeleton diagram showing a configuration of a drive system of a conventional continuously variable transmission having such a structure. FIG. 4 is an enlarged sectional view of a portion corresponding to a portion A in FIG. 3 of the conventional continuously variable transmission, and FIG. 5 is an explanatory diagram showing a state where the continuously variable transmission is mounted on a vehicle.

The continuously variable transmission shown in FIG. 3 uses a torque converter 1 as the starting device. An oil pump (hydraulic power source) 3 and a forward / reverse switching mechanism are provided between the torque converter 1 and the main transmission mechanism 2. The configuration is such that the mechanism 4 is arranged. Then, the continuously variable transmission is mounted together with the engine 16 as a transmission 15 in front of the vehicle as shown in FIG. 5, and transmits the driving force of the engine 16 to the drive wheels 18 by appropriately shifting the rotational driving force.

Here, the main transmission mechanism 2 is mounted on a primary shaft (input shaft) 32 to which rotational driving force is input from the engine 16 via the torque converter 1, and mounted on an output shaft 37 for driving. The secondary pulley 6 outputs a rotational driving force to the wheel 18 side, and a metal belt (drive belt) 7 that transmits rotation from the primary pulley 5 to the secondary pulley 6. Also,
Movable sheaves 8, 9 are incorporated in the primary pulley 5 and the secondary pulley 6, respectively, so as to be movable in the axial direction by ball splines 36. Further, hydraulic chambers 10 and 11 are provided on the rear side of the movable sheaves 8 and 9, and by appropriately controlling the pressure in the hydraulic chambers 10 and 11, the movable sheaves 8 and 9 slide in the axial direction. The pulley groove widths of the primary pulley 5 and the secondary pulley 6 can be changed. As a result, the winding diameter of the metal belt 7 changes, and an arbitrary speed ratio can be obtained in a stepless manner.

Each of the hydraulic chambers 10 and 11 has an oil pump 3
A primary pressure and a secondary pressure obtained by adjusting the original pressure generated by the control valve by a control valve (not shown) are applied. In this case, a line pressure corresponding to the gear ratio is applied to the secondary pulley 6 side as a secondary pressure, and a necessary tension is applied to the metal belt 7. On the other hand, the hydraulic chamber 10 on the primary pulley 5 side has a larger cross-sectional area than the hydraulic chamber 11 on the secondary pulley 6 side, to which a pressure reduced in line pressure is applied as a primary pressure. In this case, the primary pressure is adjusted by the engine speed and the depression depth of the accelerator pedal. When the primary pressure is increased and oil is supplied, the groove width of the primary pulley 5 becomes narrow, the diameter on the drive side becomes large, and the speed is shifted to the high speed side (overtop side). Further, when the primary pressure is lowered and oil is drained, the groove width is widened, the diameter on the drive side is reduced, and the speed is shifted to a low speed side (low side). In addition,
In FIG. 4, the upper half shows a state in which the primary pressure has decreased and has shifted to a lower speed side, and the lower half shows a state in which the primary pressure has increased and has shifted to a higher speed side.

On the other hand, in a continuously variable transmission, when the vehicle is rapidly accelerated or decelerated, the movable gear sheaves 8 and 9 are rapidly slid to change the gear ratio abruptly. Therefore, it becomes necessary to supply a large amount of oil to the hydraulic chamber 10 or 11 instantaneously. Therefore, the primary pressure circuit and the secondary pressure circuit that supply oil to the hydraulic chambers 10 and 11 are formed to secure a flow path cross-sectional area that can sufficiently cope with a required oil amount. In view of this, in the case of a continuously variable transmission, a supply circuit for the primary pressure is conventionally provided so that the primary pressure is supplied from a control valve (not shown) through the case housing 31, from the end of the primary shaft 32 to the primary shaft 32, and to the hydraulic chamber 10. Have been placed. In this case, as the primary pressure circuit having such a path, due to the structure of the continuously variable transmission, a configuration in which it is passed from the outer wall side of the case housing 31 and a configuration in which it is passed from the engine 16 side are conceivable.

The continuously variable transmission shown in FIG. 3 employs the former configuration. As shown in FIG. 4, a primary pressure circuit 13 is provided in a cover 33 formed separately from the case housing 31. Is provided. In this case, in the primary pressure circuit 13 of FIG.
An oblique hole 14 is formed along the case housing 31 and communicates with one end of an oil passage 34 formed integrally with the oil passage 34. This is to prevent the primary pressure circuit 13 from increasing the overall length of the transmission 15. The oil passage 34 is bent at a right angle from the middle, and the other end side is formed to protrude from the cover 33 in a hollow shaft shape. Then, the outer periphery thereof is processed to incorporate a seal ring, and fitted into an axial oil passage 35 formed in the primary shaft 32.

When the primary pressure circuit is passed from the engine 16 side, since the oil pump 3, the forward / reverse switching mechanism 4, the bearing for supporting the primary shaft and the like are present on the engine 16 side, the primary pressure circuit is connected to the inside of the oil pump. Through.

[0009]

By the way, as shown in FIG. 5, in front of the vehicle body, outside the power unit including the transmission 15 and the engine 16, the structure of the vehicle body absorbs the impact at the time of collision. Body frame 1
7 are provided. Further, a drive wheel 18 which is a front tire exists outside the frame 17. in this case,
The rigidity of the frame 17 must be increased in order to improve steering stability and collision safety. In addition, it is necessary to set a sufficient steering angle of the front tire in order to make the vehicle easier to handle. Further, in order to improve efficiency including fuel efficiency, the vehicle body must be reduced in weight and size. On the other hand, in the case of a vehicle model in which the transmission is mounted horizontally in front of the vehicle body, the total length of the transmission directly affects the total length of the power unit including the engine. Therefore, in order to secure the steering angle space while securing the frame rigidity and further reduce the size of the vehicle body, it is necessary to shorten the entire length of the power unit including the transmission as much as possible.

However, in the conventional continuously variable transmission as shown in FIG. 3, an oil passage 34 is provided in a cover 33, and this end is fitted to a primary shaft 32 to form a primary pressure circuit 13. As a result, the cover 33 becomes thicker to form the oil passage 34. When the cover 33 is manufactured, a mold having a pin fitted to the oil passage 34 is used to form the oil passage 34. in this case,
Since the pins are implanted in the mold, the cross-sectional shape of the pins needs to be circular at least at the root in consideration of workability. For this reason, the dimension from the end of the primary shaft 32 to the end face of the cover 33 must be large enough to implant the pin. Accordingly, there is a problem that the size of the cover 33 increases accordingly, and the overall length X of the transmission (see FIG. 3) increases.

On the other hand, from the control valve to one end of the oil passage 34, a primary pressure circuit 13 is formed by an oblique hole 14 along the case housing 31.
However, such an oblique hole cannot be formed only by the main mold when the case housing 31 is formed.
It must be formed by a mold using a core or a pin, or drilled after forming. However, when a core is used, there is a problem in that the mold structure is complicated, the mold cost is increased, the number of manufacturing steps is increased, and the cost is increased. In addition, core residues tend to remain in the holes formed by the core, which may adhere to a control valve or the like and cause malfunction.

When the holes 14 are formed by pins, the holes 14 are oblique, so that a mold that moves in a direction different from the main mold splitting direction is required for inserting and removing the pins. For this reason, similarly to the case of using a core, there is a problem that the mold structure is complicated, the mold cost is increased, the molding time is increased, and the cost is increased.

On the other hand, in the case of drilling, the mold structure is simplified, but the cost is increased by the additional machining step after molding. Also, in the case of machining, the processed part is formed thick to secure a processing margin, but nests are easily formed in the thick part of the cast product, and when drilling there, nests may exist in the processing hole part And there is a problem of causing oil leak.

An object of the present invention is to reduce the overall length of a continuously variable transmission and to simplify the structure of the transmission to simplify the mold structure and reduce the manufacturing cost.

[0015]

SUMMARY OF THE INVENTION Among the inventions disclosed in the present application, typical ones will be briefly described as follows.

That is, in the continuously variable transmission according to the present invention, a drive belt is provided between a primary pulley mounted on an input shaft and having a variable pulley groove width to which engine rotation is transmitted, and the primary pulley mounted on an output shaft. A secondary pulley with a variable pulley groove width is housed in a case housing, and the primary pulley is operated via a shaft-side oil passage formed in the input shaft and opened at an end face opposite to the engine. A continuously variable transmission that supplies a primary pressure to be applied from a hydraulic source, wherein the input shaft is sealed to the case housing so that an opening of the shaft-side oil passage faces the outside of the case housing, and the input shaft is mounted on the case housing. A housing-side oil passage is formed which is connected to the oil supply side and is opened at an end surface of the case housing opposite to the engine, and an opening of the shaft-side oil passage and the housing-side oil A cover member having a space covering the opening is attached to the end surface of the case housing in a state where the space is sealed, and the opening of the shaft-side oil passage and the opening of the housing-side oil passage communicate with each other through the space. It is characterized by becoming. Thereby, a primary pressure circuit is formed from the oil passage on the housing side to the oil passage on the shaft side via the space in the cover. In this case, unlike the conventional continuously variable transmission, the primary pressure circuit in the cover can be formed without using pins, so that the cover can be formed thin and the overall length of the transmission can be shortened.

In this case, the oil passage on the housing side is connected to the first oil passage along the drawing direction of the mold forming the end face of the case housing and the drawing direction of the mold forming the connection surface between the case housing and the hydraulic pressure source side. The second oil passage may be formed along the second oil passage. This eliminates the necessity of a split die and a core for forming the oil passage, thereby simplifying the mold structure and reducing the cost of the mold and the molding time. .

Further, a sliding holding member may be provided between the case housing and the input shaft for holding the end of the input shaft opposite to the engine in a state sealed with the case housing. No post-processing is required, and the number of man-hours can be reduced accordingly.

[0019]

Embodiments of the present invention will be described below in detail with reference to the drawings.

(Embodiment 1) FIG. 1 is an enlarged sectional view showing a part of a continuously variable transmission according to Embodiment 1 of the present invention. It is an enlarged view of a corresponding part. The basic structure of the continuously variable transmission is the same as that shown in FIG. 3, and the same reference numerals are given to the same members, and the details are omitted.

As in the case of the continuously variable transmission of FIG. 3, the continuously variable transmission supplies the primary pressure from the end of the primary shaft 21 on the side opposite to the engine. That is, the primary shaft 21 is connected to the shaft-side oil passage 35 (hereinafter referred to as the oil passage 35) communicating with the hydraulic chamber 10 (see FIGS. 3 and 4).
) Is formed, and the primary pressure is supplied to the hydraulic chamber 10 via the oil passage 35. Then, by adjusting the primary pressure appropriately and refueling or draining,
The movable sheave 8 (see FIGS. 3 and 4) accommodated in the case housing 22 is slid in the axial direction to obtain an arbitrary gear ratio.

Here, the case housing 22 is provided with a shaft hole 22b at an end face 22a thereof, and the end of the primary shaft 21 projects outside the case housing 22 from the shaft hole 22b. . In this case, the O-ring 2 is attached to the primary shaft 21.
3 is attached and passed through the shaft hole 22b in a sealed state. Also, the case housing 22
A bearing 24 is mounted in the inside, and one end side of the primary shaft 21 is supported by the bearing 24. Note that the bearing 24 includes a spacer 38
And a lock nut 39, which is attached to the primary shaft 21 and fixed to a bearing holding portion 22 d of the case housing 22.

Further, the case housing 22 has
, A housing-side oil passage 25 (hereinafter referred to as an oil passage 25) extends from below the shaft hole 22b to the bearing holding portion 22d.
). Then, oil is supplied to the oil passage 25 from a control valve (not shown) connected to the oil pump 3 (see FIG. 3), which is a hydraulic pressure source, in the direction of the arrow in the figure.

As shown in FIG. 1, the oil passage 25 has an end surface side oil passage 25a (first oil passage) and a mating surface side oil passage 25b (second oil passage).
The case housing 22 is formed by an oil passage).
Inside, it is bent at right angles. That is,
The end face side oil passage 25a is connected to the end face 22 of the case housing 22.
a, and extends rightward in the figure in parallel with the primary shaft 21. The mating surface side oil passage 25b extends from the mating surface (connection surface) 22c of the case housing 22 with the control valve toward the right end of the end surface side oil passage 25a.

Here, the case housing 22 is made of aluminum die cast, and the end face side oil passage 25a and the mating face side oil passage 25b are also formed by casting. In this case, the end face side oil passage 25a is formed by deeply removing the casting in the same direction as the drawing direction of the mold forming the end face 22a. The mating surface side oil passage 25b is formed in the same direction as the direction in which the mold forming the mating surface 22c is removed. That is, in the case housing 22 shown in FIG. 1, the oil passage 25 is formed by a hole extending in the direction in which the mold is removed, and can be easily formed by a pin provided in the mold. Therefore, in the case housing 22, unlike the case housing 31 in FIG. 4, it is not necessary to set a split mold or a core in another direction only for the oil passage hole 14. Therefore, the mold structure can be simplified, the molding time of the case housing can be shortened, and the cost can be reduced.

On the other hand, the end surface 22a of the case housing 22
The cover 27 is connected to a bolt 28 via a gasket 26.
Installed by. A space 27a is formed on the right side of the cover 27 in the drawing.
The end of the primary shaft 21 is accommodated in 7a. The space 27a also covers the opening of the end face side oil passage 25a, and the space 35a simultaneously covers the opening 35a of the oil passage 35 and the opening 25c of the oil passage 25. Therefore, the oil passage 25 is formed in the space 2
It will communicate with the oil passage 35 in a sealed state via 7a. Thus, a primary pressure circuit 13 is formed from the control valve to the hydraulic chamber 10 via the oil passage 25, the space 27a, and the oil passage 35.

In this case, the flow path cross-sectional area of the primary pressure circuit 13 at the cover 27 is determined by the area of the space 27a and the distance between the end of the primary shaft 21 and the bottom of the space 27a. . For this reason, by expanding the space 27a in the radial direction, the distance can be reduced while securing a necessary flow path cross-sectional area, and the cover 27 can be thinned. Therefore, according to the configuration of the present invention, the axial dimension of the continuously variable transmission can be reduced as compared with the structure in FIG. Becomes possible.

In the continuously variable transmission having the above-described structure, the width of the pulley groove of the primary pulley is changed by appropriately controlling the primary pressure similarly to the above-described conventional continuously variable transmission, so that the continuously variable transmission can be performed. Is performed. That is, the primary pressure is supplied or discharged from the control valve to the hydraulic chamber 10 through the oil passage 25, the space 27a, and the oil passage 35, and the movable sheave moves in the axial direction by the hydraulic pressure to change the pulley groove width of the primary pulley. I do. Note that these shift operations are the same as the operations described in the conventional continuously variable transmission shown in FIG.

(Second Embodiment) Next, a continuously variable transmission according to a second embodiment of the present invention will be described. FIG. 2 is an enlarged sectional view showing a part of a continuously variable transmission according to a second embodiment of the present invention. The same members as those of the continuously variable transmission in FIG. 1 are denoted by the same reference numerals, and the details thereof are omitted.

The continuously variable transmission shown in FIG. 2 differs from the continuously variable transmission shown in FIG.
The sleeve (sliding holding member) 41 is attached to the shaft hole 22b while the end of the primary shaft 21 is inserted through the shaft hole 22b. The other components are the same as those of the continuously variable transmission shown in FIG.

In this case, in the continuously variable transmission shown in FIG. 1, the O-ring 23 and the inner surface of the shaft hole 22b slide directly with the rotation of the primary shaft 21.
It is necessary to grind the inner surface of 2b to prevent the O-ring 23 from deteriorating. On the other hand, in the continuously variable transmission of FIG.
Since the O-ring 23 slides on the inner surface of the sleeve 41, there is no need to process the inner surface of the shaft hole 22b. As described above, in the continuously variable transmission shown in FIG. 2, the post-processing of the inner surface of the shaft hole 22b is not required, so that the number of man-hours can be reduced and the cost can be further reduced.

Although the invention made by the inventor has been specifically described based on the embodiment, the invention is not limited to the embodiment and can be variously modified without departing from the gist of the invention. Needless to say,

For example, in FIGS.
a and the mating surface side oil passage 25b are formed perpendicular to the end surface 22a and the mating surface 22c, respectively. However, the end surface side oil passage 25a and the mating surface side oil passage 25b form the end surface 22a and the mating surface 22c. As long as it is formed along the direction in which the mold is removed, it is not necessarily required to be perpendicular to the end face 22a or the mating face 22c, and it is not necessary that the end face side oil passage 25a and the mating face side oil path 25b intersect perpendicularly. .

Further, in the above-described continuously variable transmission, the space 27a is formed with a gasket 26 to prevent leakage of the primary pressure.
But gasket 26 is replaced with O
Sealing may be performed using a ring.

[0035]

Advantageous effects obtained by typical ones of the inventions disclosed in the present application will be briefly described.
It is as follows.

(1) The opening of the shaft-side oil passage facing the outside of the case housing in the sealed state and the opening of the housing-side oil passage connected to the control valve are connected to a cover having a space covering both openings. By covering these openings in a sealed state and communicating these openings in a sealed state with the outside,
The oil passage in the cover can be formed without using pins, and the distance between the end of the primary shaft and the bottom of the space of the cover can be set small. Therefore, the cover can be made thinner, and the overall length of the transmission can be reduced.

(2) Since the oil passage on the housing side is composed of two oil passages extending in the direction in which the mold is removed, a split mold and a core for forming the oil passage are not required, and the structure of the mold is simplified. Can be. Therefore, the mold cost can be reduced,
The molding time can be shortened, and the manufacturing cost of the continuously variable transmission can be reduced.

(3) Since the sleeve is provided between the case housing and the primary shaft, post-processing of the case housing is not required, so that the number of man-hours can be reduced and the cost is further reduced. be able to.

[Brief description of the drawings]

FIG. 1 is an enlarged sectional view showing a part of a continuously variable transmission according to a first embodiment of the present invention in an enlarged manner.

FIG. 2 is an enlarged sectional view showing a part of a continuously variable transmission according to a second embodiment of the present invention in an enlarged manner.

FIG. 3 is a skeleton diagram showing a configuration of a drive system of a conventional continuously variable transmission.

FIG. 4 is an enlarged sectional view of a portion corresponding to a portion A in FIG. 3 in the conventional continuously variable transmission.

FIG. 5 is an explanatory diagram showing a state in which the continuously variable transmission is mounted on a vehicle.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Torque converter 2 Main transmission mechanism 3 Oil pump (oil pressure source) 4 Forward / reverse switching mechanism 5 Primary pulley 6 Secondary pulley 7 Metal belt (drive belt) 8 Movable sheave 10 Hydraulic chamber 11 Hydraulic chamber 13 Primary pressure circuit 14 Hole 15 Transmission 16 Engine 17 Frame 18 Drive wheel 21 Primary shaft (input shaft) 22 Case housing 22a End face 22b Shaft hole 22c Fitting face (connection face) 22d Bearing holding part 23 O-ring 24 Bearing 25 Housing side oil path 25a End side oil path (first) Oil passage) 25b Fitting surface side oil passage (second oil passage) 25c Opening 26 Gasket 27 Cover 27a Space 28 Bolt 31 Case housing 32 Primary shaft (input shaft) 33 Cover 34 Oil passage 35 Shaft side oil passage 3 a opening 36 a ball spline 37 the output shaft 38 a spacer 39 a lock nut 41 sleeve (sliding retention member)

Claims (3)

[Claims] 1. A variable pulley groove width primary secondary pulley mounted on an input shaft and transmitting engine rotation, and a variable pulley groove width secondary pulley mounted on an output shaft and spanning the primary pulley. A pulley is housed in a case housing, and a primary pressure for operating the primary pulley is supplied from a hydraulic pressure source through a shaft-side oil passage formed in the input shaft and opened at an end face opposite to the engine. A continuously variable transmission, wherein the input shaft is sealed to the case housing so that an opening of the shaft-side oil passage faces the outside of the case housing, and the input shaft is connected to the hydraulic power source side. A housing-side oil passage opening at an end surface of the case housing opposite to the engine; and an opening of the shaft-side oil passage and the housing. A cover member having a space covering the opening of the side oil passage is attached to the end face of the case housing in a state where the space is sealed, and the opening of the shaft-side oil passage and the opening of the housing-side oil passage are connected to the space. A continuously variable transmission characterized in that it is communicated via a part. 2. The continuously variable transmission according to claim 1, wherein the housing-side oil passage includes a first oil passage along a direction in which a mold forming the end surface of the case housing is removed, and the case housing. And a second oil passage extending along a direction in which a mold forming a connection surface with the hydraulic pressure source side is formed. 3. The continuously variable transmission according to claim 1, wherein an end of the input shaft opposite to the engine is sealed between the case housing and the input shaft with the case housing. A continuously variable transmission provided with a sliding holding member for holding the sliding member in a fixed state.