JPH077648Y2 - Lubrication structure of automatic transmission - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial field of application) The present invention relates to a lubricating structure for supplying lubricating oil to a lubricating portion such as a clutch in an automatic transmission mounted on an automobile.

(Prior Art) Generally, an automatic transmission for an automobile is disclosed in
As described in Japanese Patent Laid-Open No. 54-132066, oil pressurized by an oil pump is supplied to a torque converter as working oil, and the working oil is further supplied to each lubricating portion of an automatic transmission through an oil cooler. I am trying to supply it as. However, if the oil from the oil pump is supplied to the lubrication portion via the torque converter and the oil cooler in this way, the lubrication path has a large flow path resistance, so the pump capacity must be increased to some extent. Insufficient amount, especially at high rotation, causes poor lubrication and seizure of the clutch occurs. However, if the pump capacity is increased in order to secure the amount of lubricating oil, the size of the pump increases, driving resistance increases, and the fuel efficiency of the engine deteriorates.

Therefore, a bypass passage is provided to bypass the torque converter and the oil cooler and directly supply the oil from the oil pump to the lubrication unit.In the high rotation range where clutch burn or the like is likely to occur, a large amount of oil is passed through the bypass passage to the clutch or the like. A method of additionally supplying the lubricating oil is being considered.

By the way, when the lubricating path is configured to supply the lubricating oil through the bypass passage in addition to the lubricating oil supplied through the oil cooler as described above, the total amount of the lubricating oil supplied to the lubricating portion of the automatic transmission is However, the back pressure of the oil cooler increases at the same time, and the amount of lubricating oil supplied through the oil cooler may decrease, which may reduce the cooling performance of the oil cooler.

(Object of the Invention) The present invention has been made in view of the above problems, and lubrication of an automatic transmission capable of ensuring a sufficient amount of lubricating oil in a high rotation range and at the same time maintaining a predetermined cooling performance by an oil cooler. The purpose is to get the structure.

(Constitution of the Invention) The lubrication structure of the automatic transmission according to the present invention has a lubrication path that guides the oil discharged from the oil pump of the automatic transmission to the lubrication portion via the torque converter and the oil cooler at the time of high engine rotation. A bypass passage for directly supplying oil from the oil pump to bypass the torque converter and the oil cooler, and closing the bypass passage to connect the lubricating oil passage from the oil cooler to the lubricating portion of the automatic transmission. And a second position in which the bypass passage is in communication with the passage portion and the lubricating oil passage from the oil cooler is in direct communication with the oil pan. It is characterized by that.

(Operation) During normal operation, the bypass passage is closed and the switching means is controlled to the first position where the lubricating oil passage from the oil cooler is communicated with the passage portion reaching the lubrication portion of the automatic transmission. The generated oil is supplied to the lubrication section of the automatic transmission through the torque converter and the oil cooler. Further, at the time of high engine speed, the switching means is switched to the second position where the bypass passage is communicated with the passage portion reaching the lubrication portion and the lubricating oil passage from the oil cooler is directly communicated with the oil pan, and the automatic transmission is performed. A large amount of oil discharged from the oil pump is supplied to the lubrication section of the machine through the bypass passage. Further, at this time, an oil path that flows from the oil pump to the coil cooler via the torque converter and returns directly into the oil pan is formed independently of the bypass passage, and therefore, the amount of oil flowing through the cooler is secured and cooling performance is maintained. To be done.

(Examples) Examples will be described below with reference to the drawings.

FIG. 1 shows a lubricating oil passage in an automatic transmission according to an embodiment of the present invention. The oil in the oil pan 2 provided in the lower portion of the transmission housing 1 is sucked from the suction port 4 of the gear type oil pump 3, pressurized, and then discharged from the discharge port 5. The oil sent out by the pump 3 enters the valve body 6 to be pressure-controlled, and is sent to the torque converter 7 as working oil. Then, after this hydraulic oil is guided from the torque converter 7 to the oil cooler 8 and cooled, it enters the lubricating oil passage 11 in the pump housing 10 via the switching control valve 9 and enters the pump housing 10
Through the passage formed by the groove portion 12a on the side of the pump and the groove portion 12b on the side of the pump cover 13 into the lubricating oil passage 14 formed in the radial direction of the pump cover 13. Then, it is sent to each lubrication portion in the transmission housing 1 through a gap portion around the pump shaft (not shown). Further, a groove portion 15 is provided on the end surface of the pump housing 1 on the pump cover 13 side so that one end is opened to the passage portion 5b from the discharge port portion 5a of the pump 3 to the discharge port 5, and this is a lubrication for bypass in the pump housing 1. By communicating with the oil passage 16, a bypass path for directly supplying the lubricating oil from the oil pump 3 via the switching control valve 9 is formed.

As shown in FIG. 2, the pump 3 includes a pump housing 10
Outer gear 17 and inner gear 18 are
On the other hand, when the inner gear 18 rotates, oil is sucked from the suction port 4 and discharged from the discharge port 5.

A spool 20 biased by a spring 19 in a direction against the discharge pressure is provided in the discharge side passage portion 5b. The oil pressurized by the pump 3 flows through the spool 20 and is discharged from the discharge port 5. Further, a drain passage 21 communicating with the suction port portion 4a is opened in the passage portion 5b.

The spool 20 is provided with a drain hole 22. When the pump speed increases and the spool 20 moves against the spring force, the drain hole 22 begins to be aligned with the opening 21a of the drain passage 21. Then, the excess oil is returned to the suction port 4a side through the drain passage 21, so that the discharge amount of the oil is controlled to a substantially constant amount.

Further, the groove portion 15 of the pump housing 1 communicating with the bypass lubricating oil passage 16 is opened by the spool 20 after the oil outflow to the drain passage 21 is started.
When the engine reaches a predetermined high engine speed range, the switching control valve 9 switches the lubrication path to the bypass path side.
On the other hand, the oil sent through the oil cooler 8 is directly returned to the oil pan 2.

FIG. 3 is an external view of this embodiment. As shown in this figure, an oil pump 3 is provided at the rear end of the transmission housing 1, and an oil pan 2 is provided below the housing 1. A differential case 22 is integrally provided on one side of the transmission housing 1, and a valve body 6 is formed on the side opposite to the differential case 22. The oil cooler 8 is located on the valve body 6 side and is arranged toward the front of the vehicle. Between the transmission housing 1 and the upper part of the oil cooler 8, oil from the torque converter 7 is placed between the oil cooler 8 and the oil cooler 8.
An oil pipe 23 that leads to the lubricating oil pipe 24 (24a, 24a, between the lower part of the oil cooler 8 and the lubricating oil passage 11 in the oil pump 3).
24b) is provided. The lubricating oil pipe 24 communicates with the lubricating oil passage 11 in the oil pump 3, and the switching control valve 9 is provided on the way. A bypass oil pipe 25 extending from the bypass lubricating oil passage 16 in the oil pump 3 and a drain pipe 26 reaching the oil pan 2 are connected to the switching control valve 9.

FIG. 4 shows the structure of the switching control valve 9 and its operating state. The figure (a) shows the state at the time of engine low rotation, and the figure (b) shows the state at the time of engine high rotation. The switching control valve 9 is composed of a hydraulically operated switching valve 27 and a solenoid valve 28 for controlling the hydraulic pressure of the switching valve 27.
Includes a cylindrical valve body 29, and a spool 31 biased in one direction by a spring 30 inside the valve body 29. The valve body 29 has a first opening 32 communicating with the lubricating oil 24a from the oil cooler 8 and a second opening 33 communicating with the bypass oil pipe 25 from the oil pump 3.
And an oil pipe connected to the lubricating oil passage 11 in the oil pump 3 leading to the lubrication portion of the transmission housing 1.
Third and fourth openings 34, 35 communicating with 24b and a fifth opening 36 opening in the drain pipe 26 to the oil pan 2 are provided. On the other hand, the spool 31 has first and second annular grooves 37 and 38, and the spring 30 is mounted in a compressed state between a blind plug 39 that closes one end of the valve body 29 and the spool 31. Further, an oil hole 40 for introducing an operating pressure is provided at the other end of the valve body 29.
Are formed.

The solenoid valve 28 is configured to open when power is supplied to drain the operating pressure of the switching valve 27, and to close the drain passage when power is cut off.

In a normal operating range in which the engine speed does not reach the predetermined speed, the solenoid valve 28 is energized, and the spool 31 is pressed fully by the spring force as shown in FIG. 4 (a). Held in position. At this time, the first opening 32 communicates with the third opening 34 via the first annular groove 37, and the communication between the second opening 33 and the fourth opening 35 is blocked. Therefore, the oil cooler 9 is installed in the lubrication part.
Oil is supplied from. Further, in the high rotation speed range where the engine speed is equal to or higher than the predetermined speed, the solenoid valve 28 is de-energized, and as shown in FIG.
Is moved by hydraulic pressure to the second one, which balances the spring force. At this time, the first opening 32 communicates with the fifth opening 36, the oil from the oil cooler 8 is returned to the oil pan 2 as it is, and the second opening 33 forms the second annular groove.
The oil from the oscill pump 3 is directly sent to the lubrication part by communicating with the fourth opening 35 via 38.

In the above embodiment, the gear type oil pump has been described, but the present invention can be applied to vane type oil pumps having other oil pumps.

(Effect of the Invention) Since the present invention is configured as described above, the oil pump directly supplies oil to the lubrication section through the bypass passage having a small flow resistance in the high rotation range, thereby making the pump large in size. It is possible to secure a sufficient amount of lubricating oil without liquefying, and to prevent the back pressure of the oil cooler from rising due to the supply of lubricating oil through the bypass passage, and to maintain a predetermined cooling performance by the oil cooler. it can.

[Brief description of drawings]

FIG. 1 is an explanatory view showing a passage of lubricating oil in an embodiment of the present invention, FIG. 2 is an internal structure part of an oil pump in the embodiment, FIG. 3 is an external view of the embodiment, and FIG. a),
(B) is explanatory drawing which shows the structure and operating state of the switching control valve in the same Example. 1: Transmission housing, 2: Oil pan, 3: Oil pump, 7: Torque converter, 8: Oil cooler, 9:
Switching control valve, 11: lubricating oil passage, 15: groove portion, 16: bypass lubricating oil passage, 23: oil pipe, 24: lubricating oil pipe, 25: bypass oil pipe, 26: drain pipe.

 ─────────────────────────────────────────────────── ─── Continuation of front page (72) Tatsuro Kubo 3-1 Shinchi, Fuchu-cho, Aki-gun, Hiroshima Prefecture Mazda Co., Ltd. (56) References JP-A-54-132066 (JP, A)

Claims (1)

[Scope of utility model registration request] Claim: What is claimed is: 1. An oil from an oil pump of an automatic transmission is introduced into a lubrication path through a torque converter and an oil cooler to a lubrication section. A bypass passage for bypassing and directly supplying the bypass passage, and closing the bypass passage to connect the lubricating oil passage from the oil cooler to a passage portion reaching the lubricating portion; A lubricating structure for an automatic transmission, characterized in that switching means is provided for switching control to a second position where the lubricating oil passage from the oil cooler is directly communicated with the oil pan.