JPH02278042A - Automatic transmission - Google Patents

Abstract

PURPOSE:To suppress wear of a gearing engaging part as much as possible by a method wherein a first power transmission member is formed by a green material, and an ion nitriding treatment part is formed on the given region of the first power transmission member containing an engaging part geared with a third power transmission member. CONSTITUTION:A direct clutch C2 and a drum can gear input 101 are provided between an input shaft 20 and a sun gear 25a of a front planetary gear unit 14. A plurality of teeth 104a are formed in the opposing end parts of a clutch drum 104 and the gear 101 additionally used for a brake drum, and the drum 104 is formed by a press green material. Meanwhile, a number of spline teeth 101a are formed in the inner peripheral end of the gear 101 and spine-engaged with the gear 25a formed by a cementation quenched material. The gear 101 is formed by a green material, ion nitriding treatment is applied on a region (a) containing an engaging part with the gear 25a, and a part except the region is left made of a press material. A number of teeth 101b engaged with the gear 104 are formed in the outer peripheral end of the gear 101.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to an automatic transmission equipped with a planetary gear transmission mechanism consisting of a front planetary gear unit and a rotational unit for use in vehicles such as automobiles. be.

[Prior Art] Conventionally, automatic transmissions for automobiles equipped with a planetary gear transmission mechanism include several multi-disc clutches and multi-disc brakes in order to change the power transmission path in the planetary gear transmission mechanism during gear shifting. It is provided.

By the way, in such an automatic transmission, for example, D
At 3rd and 4th speeds in the range, 3rd speed in the 2nd range, or reverse in the R range, the power of the input shaft is directly transmitted rearward, bypassing the front planetary gear unit of the planetary gear transmission mechanism.

A direct clutch and drum sun gear input are provided for this direct power transmission. This drum sun gear input meshes with the drum of the direct clutch in an X-engagement, and is spline-fitted to the sun gear of the front planetary gear unit, which is integrally formed with the sun gear of the rear planetary gear unit.

In that case, since the sun gear is made of a hardened material that has been carburized and quenched, the drum sun gear input is made of pressed raw material that has been subjected to a nitriding process called tuftride treatment in order to prevent friction caused by engagement with the sun gear. It is formed by In that case, since this tuftride treatment is generally performed in air, it is extremely difficult to perform partial treatment. Therefore, the entire drum sun gear input is treated with Tufftride.

[Problems to be Solved by the Invention] However, if the entire drum sun gear input is subjected to Tufftride treatment in this way, the drum of the direct clutch that meshes and engages with this unit will wear out. The brake drum is often used as a brake drum, and it is necessary to ensure a certain degree of surface accuracy for the brake surface, so it is made of pressed raw material. For this reason, the hardness of the clutch drum and drum sun gear input are different from each other, especially D
When downshifting from 3rd gear to 2nd gear in range and 2nd range, or when reverse shifting in R range, the clutch teeth collide with the teeth of the drum sun gear input. As a result, the less hard clutch will experience friction.

Due to this friction, the gap between the two teeth becomes larger, which not only causes rattling noise, but also generates foreign matter such as chips, which can clog the strainer in the hydraulic circuit and cause the valve spool to stick. I can think of something to do.

The present invention has been made in view of these problems, and its purpose is to provide an automatic transmission that can suppress friction in the meshing engagement portions as much as possible.

[Means for Solving the Problems] In order to solve the problems, the present invention provides, for example, the third problem.
4, the input shaft (20) and the sun gear (25) of the front planetary gear unit (14) are shown.
a), a direct clutch C2 and a drum sun gear input (101) are provided.

Clutch C2 is rotatably connected to a clutch hub (103) fixed to the cylinder part (102) of forward Clara'F-C1, which is integrally formed with the input shaft (20), and a support member fixed to the case (6). A second coast brake B is provided between the clutch drum (104) supported by the clutch drum (104) and the case (6), and in this case, the clutch drum (104) is also used as a brake drum. Furthermore, a plurality of teeth (10) are provided at the end of the clutch drum (104) facing the drum sun gear input (101)
Ja, ), (104a), ... are formed. This clutch drum (104) is formed from pressed raw material.

On the other hand, the drum sun gear input (101) has a large number of spline teeth (101a) formed at its inner peripheral end, and is spline-fitted to the sun gear (25a) made of carburized and quenched material. This drum sun gear input (101) is formed from pressed raw material, and the region (a) including the fitting portion with the sun gear (25a) is subjected to ion nitriding treatment. This ion nitriding treatment ensures that the hardness of the area a of the drum sun gear input (101) is at a predetermined level. The portion of the drum sun gear input (101) other than area a is left as pressed raw material. This drum sun gear input (10
A large number of teeth (101b) that mesh with the teeth (104a) described above are also formed at the outer peripheral end of 1). The teeth (1,04a) of the clutch drum (104) mesh with the teeth (101b) of the drum sun gear input (101).

[Operations and Effects of the Invention] According to the present invention configured as described above, the meshing and engaging portions of the clutch drum (104) and the drum sun gear input (101) are both formed of pressed raw material. , the hardness of these engaging portions is the same. Therefore, wear of the clutch drum (104) can be reliably prevented.

By preventing wear, the gap between the teeth does not expand, which reduces the occurrence of rattling noise, and prevents the formation of foreign substances such as chips, which prevents clogging of strainers in hydraulic circuits. and valve spool sticking will be prevented.

Furthermore, since one surface treatment is performed partially, an effect of simplifying the treatment can also be obtained.

[Example] Hereinafter, an example of the automatic transmission of the present invention will be described in detail with reference to the drawings.

FIG. 1 is an overall sectional view showing an embodiment of an automatic transmission according to the present invention, and FIG. 2 is a schematic diagram of the automatic transmission.

As shown in FIGS. 1 and 2, the automatic transmission 1 includes a torque converter 2, a planetary gear transmission gear mechanism 3, and a hydraulic control device 4, each of which includes a converter housing 5, a case 6, and an extension housing. 7, accommodated in the valve body 8 and oil pan 9.

The torque converter 2 is equipped with a lock-up clutch 10 for improving power transmission efficiency, and the rotational power of the input member 11 is transferred indirectly through the oil flow inside the torque converter 2 or the lock-up clutch 10. The transmission is directly transmitted to the input shaft 12 of the transmission gear mechanism 3 by the engagement of the transmission gear mechanism 3.

Further, the speed change gear mechanism 3 has an overdrive planetary gear unit 13 and a main speed change unit 16 including a front planetary gear unit 14 and a rear planetary gear unit 15.

Here, the above-mentioned overdrive planetary gear unit 1
3 is connected to the input shaft 12 and consists of a carrier 18 that supports the planetary binion 17, a sun gear 19 that surrounds the input shaft 12, and a ring gear 21 that is connected to the input shaft 20 of the main transmission unit 16. . Furthermore, an overdrive direct clutch C@ and a one-way clutch Fs are arranged in parallel between the carrier 18 and the sun gear 19, respectively. Therefore, carrier 18
Power transmission between the sun gear 19 and the sun gear 19 is carried out in only one direction via the clutch C when the clutch C is in operation, and via the one-way clutch F when the clutch CI is not in operation. There is. Furthermore, an overdrive brake B is provided between the sun gear 19 and the case 6.
, is installed.

Next, the front planetary gear unit 14 is connected to the output shaft 2.
2, a carrier 24 supporting the planetary binion 23, and a connecting member 25 surrounding the output shaft 22.
Sun gear 25 of rear planetary gear unit 15
b, and the input shaft 2.
0 via a forward clutch C7. Further, a direct clutch C2 and a drum sun gear input 101 are connected between the input shaft 20 and the sun gear 25a, and a direct clutch C2 and a drum sun gear input 101 are connected between the sun gear 25a and the case 6.
A second coast brake B consisting of a band brake is interposed between the two.

As shown in detail in FIG. 3, the clutch C2 is connected to the input shaft 20
The cylinder portion of the forward clutch C1 is integrally fixed to the cylinder portion of the forward clutch C1.The cylinder portion of the forward clutch C1 includes a clutch hub 103 which is fixed to the cylinder portion of the forward clutch C1, and a clutch drum 104 which is rotatably supported by the case 6. A second coast brake B is provided between the clutch drum 104 and the case 6, and the clutch drum 104 is also used as a brake drum. Furthermore, as shown by the two-dot chain line in FIG. 4(B), a plurality of teeth 104a, 104a, . . . are formed at the end of the clutch drum 104 facing the drum sun gear input 101. This clutch drum 104 is formed from pressed raw material.

On the other hand, as shown in FIG. 4(A), the drum sun gear input 101 is formed into a bowl shape from pressed raw material, and has a large number of spline teeth 101a formed on the inner circumferential end, and is made of carburized and quenched material. It is spline-fitted to a sun gear 25a (shown by a two-dot chain line). In this drum sun gear input 101, an inner circumferential end region a including a fitting portion with the sun gear 25a is subjected to ion nitriding treatment.

This ion nitriding process is performed in an aqueous solution, so
The drum sun gear input 101 can be partially processed in this way. When partially processing the drum sun gear input 101, masking is first applied to the parts other than area a of the drum sun gear input bush 101, and then ion nitriding treatment is performed. . As a result, only the region a is subjected to the ion nitriding treatment.

By this ion nitriding treatment, the drum sun gear input 1
The hardness of the region a portion of 01 is ensured at a predetermined level. The portion of the drum sun gear input 101 other than the area a is left as a pressed raw material. A large number of teeth 101b that mesh with the teeth 104a described above are also formed at the outer peripheral end of the drum sun gear input 101. and,
The teeth 104a of the clutch drum 104 mesh with the teeth 101b of the drum sun gear input 101.

Further, a second brake B2 consisting of multiple discs is further disposed between the sun gear 25a and the case 6 via a one-way clutch F1.

The rear planetary gear unit 15 includes a carrier 28 that supports the planetary binion 27, and a sun gear 25b.
, and a ring gear 29 directly connected to the output shaft 22. Between the carrier 28 and the case 6, there is a 1st &
A Rev brake B3 and a one-way clutch F2 are arranged in parallel.

Further, an overdrive brake B6 is provided between the sun gear 19 and the case 6. Furthermore, Sungear 19
An annular flange 30 extending in the outer diameter direction is fixed to the flange 30 . A large number of holes or notches are formed in the flange 30, and a non-contact type speed sensor 31 such as an optical or magnetic sensor is provided in the case 6 facing the holes or notches. This speed sensor 31 detects when the overdrive direct clutch Cs is connected, that is, during 1st, 2nd, and 3rd speeds.
The rotational speed of the collar portion 30 that is integrated with the input shaft 12 is detected.

In addition, in the figure, 32 is a hydraulic pump.

On the other hand, inside the extension case 7, for example, an ECU
A vehicle speed sensor 33 that detects the rotation of the output shaft 22 for use as a control parameter for an electronic control device such as an ESC, and a rotation speed detection gear 34 that extracts the rotation speed of the output shaft 22 to transmit the vehicle speed to a vehicle speed meter are installed. ing.

The output signals from both sensors 31 and 33 are sent to a control unit along with output signals from other sensors. Based on these output signals, the control unit controls four solenoids (not shown) arranged in the hydraulic control device 4. The valves are controlled accordingly.

Next, the operation of the automatic transmission 1 configured as described above will be explained.

Each of the aforementioned clutches C, C1 and C2, which are frictional engagement elements,
and each brake Bs, Bl, B2. Bl is each range P, R, R (V≧9), N, D
, 2nd, and L are controlled according to the operation diagram shown in FIG. 2. Also, each one-way clutch Fs at each gear stage at that time,
The binding and release states of Fl and F2 are shown in the same figure, respectively.

Each clutch C,,C,,C2 and each brake Bl.

B2. The operation of B3 is controlled by the four solenoid valves in the hydraulic control device 4 described above. Setting of each range is performed by operating a manual shift valve provided in the hydraulic control device 4.

First, the case where the D range is set will be explained.

In 1st gear, overdrive direct clutch CI!
and forward clutch C5 are respectively engaged.Other clutches and brakes are controlled to be in the released state. Therefore, the overdrive planetary gear unit 13
are integrated into a directly connected state via the overdrive direct clutch C1, and the rotation of the input shaft 12 is directly transmitted to the input shaft 2o of the main transmission unit 16. Further, in the main transmission unit 16, the rotation of the input shaft 20 is transmitted to the ring gear 26 of the front planetary gear unit 14 via the forward clutch C7.
4 and the output shaft 22 integrated with the carrier 24, and applies a leftward rotational force to the carrier 28 of the rear planetary gear unit 15 via the sun gear 25b, but the one-way clutch F2 rotates the carrier 28 in this direction. To prevent rotation of the carrier 28, the carrier 28 does not rotate. As a result, the planetary binion 27 rotates and transmits power to the ring gear 29 that is integrated with the output shaft 22.

In addition, one-way clutch F is carrier 1 at this time.
It acts to engage against the rotation of 8.

Furthermore, the one-way clutch F2 becomes free when coasting.

Also, in 2nd gear, overdrive direct clutch C
1. Forward clutch C1 and second brake B
2 are respectively engaged, and the others are controlled to be in the released state. Therefore, the overdrive planetary gear unit 13
Since the input shaft 12 is maintained in a directly connected state, the rotation of the input shaft 12 is directly connected to the input shaft 20 of the main transmission unit 16 as in the case of 1st gear.
transmitted to.

Further, in the main transmission unit 16, the rotation of the input shaft 20 is transmitted to the ring gear 26 of the front planetary gear unit 14 via the forward clutch C8, and applies a leftward rotational force to the sun gear 25a via the planetary pinion 23. do. However, since the second brake B2 is engaged, the one-way clutch F1 prevents the sun gear 25a from rotating in this direction, and the sun gear 25a does not rotate.

Therefore, the carrier 24 rotates, and the second speed rotation is transmitted to the output shaft 2 via only the front planetary gear unit 14.
2.

Note that the one-way clutch F becomes free when coasting.

Furthermore, in 3rd gear, overdrive direct clutch C @, forward clutch CI, direct clutch C
2 and the second brake B2 are engaged, and the other clutches and brakes are controlled to be released. Therefore, the overdrive planetary gear unit 13 maintains a directly coupled state, and the main transmission unit 16 becomes an integrally directly coupled state with the front planetary gear unit 14 due to the engagement of the forward clutch C5 and the direct clutch C2.
The rotation of the input shaft 20 is directly transmitted to the output shaft 22.

In 4th gear, that is, the highest speed, forward clutch C, direct clutch C2 and second brake B
2 is held in the engaged state, and the overdrive direct clutch C is switched and controlled so that it is released and the overdrive brake B is engaged. Further, other brakes are controlled to be held in a released state.

In this state, the rotation of the sun gear 19 is not prevented by the overdrive brake B-, and the one-way clutch F! acts to allow the rotation of the carrier 18, so the rotation of the carrier 18 is accelerated via the planetary pinion 17 and transmitted to the ring gear 21 and input shaft 20. It becomes overdrive state. On the other hand, since the main transmission unit 16 is maintained in a directly connected state, the overdrive rotation of the input shaft 20 is directly transmitted to the output shaft 22. The output shaft 22 also becomes in an overdrive state.

On the other hand, when downshifting, in the case of 4th to 3rd speed, the overdrive direct clutch C1 is engaged and the overdrive brake Bs is released, and in the case of 3rd to 2nd speed, the direct clutch C2 is released. In the case of speed -1, the second brake B2 is released.

In addition, when driving in D range and the driver shifts down to 2nd gear using the manual valve, the second coast brake B is engaged early to prevent coasting during downshifting. We are trying to eliminate the feeling of empty running.

Next, the operation when set to the 2nd range will be explained. In the case of the 2nd range, the 1st and 3rd speeds are the same as in the case of the D range. Therefore, explanations regarding the first and third speeds will be omitted.

At the second speed, the second coast brake B1 is controlled to be engaged in addition to the forward clutch C2, the overdrive direct clutch C1, and the second brake B2. In this state, since the brake B1 is operating, the sun gear 25a of the main transmission unit 16,
25b is locked and the engine brake is activated.

In addition, when shifting up from 1st gear to 2nd gear while driving in 2nd range, by delaying engagement of second coast brake B1 to prevent second brake B2 and second coast brake B1 from engaging at the same time. , the shock given to the driver when upshifting is reduced.

Next, a case where the L range is set will be explained.

The 2nd speed in this L range is the same as the 2nd speed in the 2nd range described above. Therefore, a description of this second speed will be omitted.

In 1st speed, in addition to the forward clutch CI and the overdrive direct clutch C8, the 1st & Rev brake B is controlled to be engaged. This results in
The carrier 28 of the rear planetary gear unit 15 is locked and the engine brake is activated.

Next, the case where the G, LR, and R ranges are set will be explained.

Overdrive direct clutch C1, direct clutch C2, and brake B are not engaged, and the other clutches and brakes are controlled to be released.

Therefore, overdrive planetary gear unit 1
3 is in a directly connected state, and the rotation of the input shaft 12 is directly transmitted to the input shaft 20. In main transmission unit 16, rotation of input shaft 20 is directly transmitted to sun gears 25a, 25b by direct clutch C2. and brake B
Since the rotation of the rear carrier 28 is locked by , the rotation of the sun gears 25a, 25b is transmitted as reverse rotation to the ring gear 29 via the planetary pinion 27, and the tongue output shaft 22 is reversely rotated.

By the way, when the vehicle speed is at a predetermined speed, for example 9 km/h or higher, the direct clutch C2 is not engaged even if the manual valve is operated. This prevents the output shaft 22 from rotating in the opposite direction while the vehicle is running at a speed higher than a predetermined speed.

As is clear from the above description, according to the present invention, the first power transmission member meshingly engages with the second power transmission member having a relatively small hardness, and the first power transmission member meshingly engages with the third power transmission member having a relatively high hardness. In the transmission member, since the ion nitrided portion is formed in the portion that meshes and engages with the third power transmission member, the portion that meshes and engages with the second power transmission member is not subjected to any treatment.

Therefore, since the ion nitriding treatment of the first power transmission member increases its hardness, it is possible to reliably reduce friction even if the first power transmission member engages and collides with the third power transmission member, which is relatively hard. In addition, since the hardness of the first power transmission member and the second power transmission member is approximately the same as that of the second power transmission member, the friction of the second power transmission member is similarly reduced. You will be able to do this. Not only can this rattling sound be prevented from occurring, but also clogging of the strainer and stickiness of the vibe spool due to the generation of foreign matter can be prevented.

[Brief explanation of drawings]

Fig. 1 is an overall sectional view showing an embodiment of the automatic transmission of the present invention, Fig. 2 is a schematic diagram of the automatic transmission, Fig. 3 is a partially enlarged view of the automatic transmission, and Fig. 4 is the same. Showing the drum sun gear input used in automatic transmissions, (A)
is its front view, (B) is IVB-IV in (A)
FIG. 5 is a sectional view taken along line B, and a diagram showing the operation of each frictional engagement element. 1... Automatic transmission 12... Torque converter, 3...
・Speed gear machine #L, 4...Hydraulic control device, 5...
・Converter housing, 6... Case, 8... Valve body, 9... Oil pan, 10... Lock-up clutch, 13... Overdrive planetary gear unit, 14... Front planetary gear unit, 15 ...Rear planetary gear unit,
15... Input line 16... Main transmission unit, 20...
...Input line 22...-Output 101...Drum sun gear input, 101a...Tooth, 104...
Clutch drum, 104a...Teeth, Bl...Overdrive brake, B...Second coat clutch, C1...Forward clutch, C2...Direct clutch, Fl, Fl, F2...One-way clutch , a... Ion nitriding process Otori patent applicant Aisin ADA Co., Ltd.
Name) Representative Patent Attorney Kenji Aoki (5 others) No. 5 Procedural amendment (method) 1. Indication of the case 1999 Patent Application No. 99271 2. Title of the invention Automatic transmission 3. Person making the amendment Relationship to the case Patent applicant

Claims (2)

[Claims] (1) The planetary gear transmission mechanism meshes with a second power transmission member made of green material with relatively low hardness and a third power transmission member made of hardened material with relatively high hardness, and transmits the power of the input shaft. An automatic transmission comprising a first power transmission member that receives power from the second power transmission member and directly transmits power to the third power transmission member bypassing the planetary gear transmission mechanism, wherein the first power transmission member is made of raw material. and includes an engaging portion with the third power transmission member.
An automatic transmission characterized in that an ion nitriding treatment section is formed in a predetermined region of a power transmission member. (2) a forward crat that transmits or cuts off the power of the input shaft to the planetary gear transmission mechanism; and a direct craat that bypasses the planetary gear transmission mechanism and transmits or cuts off the power of the input shaft to the first power transmission device. 2. A clutch, wherein the second power transmission member is a drum of the direct clutch, and the third power transmission member is a sun gear of the planetary gear transmission mechanism made of a carburized and quenched material. Automatic transmission as described.