JP2013181569A - Control device of transmission - Google Patents

Abstract

PROBLEM TO BE SOLVED: To avoid degradation in durability caused by repeated over heat of a clutch without reducing the number of components of a transmission and increasing the size thereof.SOLUTION: A control device of a transmission individually calculates heat generation during switching operation of a clutch which is switched between being engaged and disengaged during shift, in other words, a reverse clutch, a forward clutch, a rear clutch, a one-way clutch, or a 2&4 brake & reverse brake. If the heat generation exceeds the predetermined threshold, switching time shortening processing is performed for shortening the time required for switching these clutches. The switching time shortening processing includes processing for increasing hydraulic pressure for operating the clutches, and processing for reducing a torque of an internal combustion engine.

Description

  The present invention relates to a transmission control device that is mounted on a vehicle and performs a shift automatically or manually.

  2. Description of the Related Art Conventionally, it is known that in an automatic transmission mounted on an automobile, a clutch is overheated when gears are continuously changed. In the past, a technique for predicting the temperature of the clutch by calculating the amount of heat generated by the clutch in consideration of the decrease in the friction coefficient caused by overheating of the clutch and controlling the clutch hydraulic pressure to compensate for the decrease in the friction coefficient due to clutch overheating has been disclosed. (For example, refer to Patent Document 1).

  However, if the clutch is overheated repeatedly due to continuous use, the durability of the clutch will be reduced. For this reason, in order to avoid this, it is necessary to increase the number of clutch plates constituting the clutch or to enlarge the clutch plate itself. As a result, the number of parts of the automatic transmission is increased and the size of the automatic transmission itself is increased.

JP 2011-33162 A

  The present invention pays attention to such inconveniences, and an object thereof is to avoid a decrease in durability due to repeated overheating of the clutch without increasing the number of parts of the transmission or increasing the size thereof.

  In order to achieve such an object, the present invention takes the following measures.

  That is, the transmission control device according to the present invention is a transmission control device that performs clutch connection / disconnection switching at the time of shifting, and calculates a heat generation amount during clutch connection / disconnection switching, and the heat generation amount is a predetermined threshold value. When exceeding the above, a switching time shortening process for shortening the time required for switching the clutch connection / disconnection is performed.

  Here, the switching time shortening process includes a process for increasing the hydraulic pressure when a hydraulic clutch is used, and a process for increasing an electrical output for operating the electromagnetic clutch when an electromagnetic clutch is used. Applicable. Further, the process for reducing the torque of the internal combustion engine in order to quickly eliminate the difference in the rotational speed also corresponds to the switching time shortening process.

  In such a case, when the heat generation amount exceeds a predetermined threshold value, the heat generation amount increases by shortening the time required for switching between clutch connection and disconnection, that is, the time in which the heat generation occurs in a so-called half-clutch state itself. Can be avoided. As a result, the amount of heat generated can be suppressed while avoiding an increase in the number and area of the clutches, and as a result, the durability of the clutch can be effectively improved.

  According to the present invention, it is possible to avoid a decrease in durability due to repeated overheating of the clutch without increasing the number of parts or increasing the size of the transmission.

1 is a schematic configuration diagram of an internal combustion engine according to an embodiment of the present invention. The schematic block diagram of the automatic transmission which concerns on the same embodiment. Structure explanatory drawing of the stepped transmission which concerns on the same embodiment. The flowchart which concerns on the same embodiment.

  An embodiment of the present invention will be described with reference to the drawings. FIG. 1 shows an outline of an internal combustion engine for a vehicle in the present embodiment.

  The internal combustion engine in the present embodiment is a spark ignition gasoline engine and includes a plurality of cylinders 1 (one of which is shown in FIG. 1). In the vicinity of the intake port of each cylinder 1, an injector 11 for injecting fuel is provided. A spark plug 12 is attached to the ceiling of the combustion chamber of each cylinder 1. The spark plug 12 receives spark voltage generated by the ignition coil and causes spark discharge between the center electrode and the ground electrode. The ignition coil is integrally incorporated in a coil case together with an igniter that is a semiconductor switching element.

  The intake passage 3 for supplying intake air takes in air from the outside and guides it to the intake port of each cylinder 1. On the intake passage 3, an air cleaner 31, an electronic throttle valve 32, a surge tank 33, and an intake manifold 34 are arranged in this order from the upstream.

  The exhaust passage 4 for discharging the exhaust guides the exhaust generated as a result of burning the fuel in the cylinder 1 from the exhaust port of each cylinder 1 to the outside. An exhaust manifold 42 and an exhaust purification three-way catalyst 41 are disposed on the exhaust passage 4.

  FIG. 2 shows an example of a drive system provided in the vehicle. This drive system includes a stepped transmission 8 which is a transmission of the present invention using a torque converter 7 and a planetary gear mechanism.

  The rotational torque output by the internal combustion engine is input from the crankshaft of the internal combustion engine to the pump impeller 71 on the input side of the torque converter 7 and transmitted to the turbine runner 72 on the output side. The rotation of the turbine runner 72 is the rotation shaft of the primary reduction driven gear 815 via the primary reduction drive gear 814 after the drive direction and the gear ratio are adjusted as appropriate after being transmitted to the input shaft 800 of the stepped transmission 8. The output shaft 815a is transmitted, and further transmitted to the output gear 101. The output gear 101 meshes with the ring gear 102 of the differential device, and rotates the axle 103 and the drive wheels (not shown) via the differential device.

  The torque converter 7 includes a lockup mechanism. The lock-up mechanism is known in this field, and a lock-up clutch 73 that fastens the input side and the output side of the torque converter 7 so as not to rotate relative to each other, and an operation for switching the connection of the lock-up clutch 73. A lock-up solenoid valve (not shown) for controlling the hydraulic pressure (hydraulic pressure) is used as an element. The lockup solenoid valve is a flow rate control valve that receives a control signal l and changes its opening.

  Generally, the lockup mechanism fastens the input side and the output side of the torque converter 7 in a situation where the gear ratio is not changed by the stepped transmission 8. During lockup, the lockup clutch 73 is pressed against the torque converter cover 74 and rotates together with the torque converter cover 74. The engine torque input to the input side (drive plate) of the torque converter 7 at the time of lock-up is output from the torque converter cover 74 via the lock-up clutch 73 and thus to the stepped transmission 8. Communicated directly to. At the time of lockup, the speed ratio, which is the ratio of the output side rotational speed of the torque converter 7 to the input side rotational speed, is 1.

  In turn, the lock-up clutch 73 is separated from the torque converter cover 74 at the time of non-lock-up. At the time of non-lock-up, the engine torque input to the input side of the torque converter 7 is transmitted from the torque converter cover 74 to the pump impeller 71 and the turbine 72 and is transmitted to the stepped transmission 8. At the time of non-lock-up, the speed ratio of the torque converter 7 becomes smaller than 1.

  A stepped transmission 8 having an internal structure shown in FIG. 3 is formed by using a planetary gear mechanism. A reverse clutch 801, a forward clutch 802, a rear clutch 803, a one-way clutch 804, and a 2 & 4 brake corresponding to the clutch of the present invention. 805 and 1 & reverse brake 806 are appropriately engaged and disengaged according to each gear position in each drive range as shown in the lower table of FIG. As a result, the rear planetary sun gear 808, the planetary carrier 809, the front planetary sun gear 810, the planetary ring gear 813, the planetary short pinion 811, the planetary long pinion 812, and the planetary ring gear 813, which are various gears, are appropriately meshed. As a result, power is transmitted from the input shaft 800 to the output shaft 815a which is the rotation shaft of the primary reduction driven gear 815 via the primary reduction drive gear 814 via the intermediate shaft 807 as the case may be. Such power is, of course, transmitted at a predetermined gear ratio and in any rotation direction according to each gear position.

In the present embodiment, the heat generation amount is calculated as follows for the shift clutch that is switched as described above. First, the average radius, differential rotation speed, and load of the clutch are obtained as in the following equations 1 to 3.
The average radius is calculated from the outer diameter and inner diameter of the clutch.

差回転数はタービン回転数及び変速進捗度（Ｘ）から算出する。

The differential rotation speed is calculated from the turbine rotation speed and the shift progress (X).

荷重は油圧、ピストン断面積及びスプリング力から算出する。

The load is calculated from the hydraulic pressure, piston cross-sectional area and spring force.

これら平均半径、差回転数及び荷重から、以下のように発熱率を算出する

From these average radii, differential rotation speed and load, the heat generation rate is calculated as follows:

そして、数５の如く、発熱率と算出間隔との積が、算出される発熱量である。

As shown in Equation 5, the product of the heat generation rate and the calculation interval is the calculated heat generation amount.

しかして本実施形態に係る変速機の制御装置たるＥＣＵ０は、変速時に断接切換がなされるクラッチすなわちリバースクラッチ８０１、フォワードクラッチ８０２、リヤクラッチ８０３、ワンウェイクラッチ８０４、２＆４ブレーキ８０５又は１＆リバースブレーキ８０６の断接切換動作中の発熱量を個別に算出し、発熱量が所定の閾値を超える場合は、これらクラッチ８０１、８０２、８０３、８０４、８０５、８０６の断接切換に要する時間を短縮するための切換時間短縮処理することを特徴とする。また「所定の閾値」とは、本実施形態では各クラッチ８０１、８０２、８０３、８０４、８０５、８０６の耐熱限界よりも低い値であり、予め各クラッチに設定された個別の値である。

Therefore, the ECU 0 serving as the transmission control device according to the present embodiment is a clutch that is switched between connection and disconnection at the time of shifting, that is, the reverse clutch 801, the forward clutch 802, the rear clutch 803, the one-way clutch 804, the 2 & 4 brake 805, or the 1 & reverse brake 806. In order to shorten the time required to switch the connection / disconnection of these clutches 801, 802, 803, 804, 805, 806 when the heat generation amount is calculated separately and the heat generation amount exceeds a predetermined threshold value. The switching time shortening process is performed. Further, the “predetermined threshold value” is a value lower than the heat resistance limit of each of the clutches 801, 802, 803, 804, 805, and 806 in the present embodiment, and is an individual value set in advance for each clutch.

  In the present embodiment, as the switching time shortening process, a process for increasing the hydraulic pressure for operating the clutches 801, 802, 803, 804, 805, and 806 and a process for decreasing the torque of the internal combustion engine are performed.

  Control during shifting according to the embodiment will be described with reference to the flowchart of FIG. The processing is always performed in the present embodiment, but may be performed only in a specific case. For example, when there is an accelerator request during continuous shifts that increase the chances of switching connection / disconnection of the clutches 801, 802, 803, 804, 805, 806, or when there is an accelerator request during irregularities, Since it takes time to engage 802, 803, 804, 805, and 806, the amount of heat generation tends to increase. The process according to FIG. 4 may be performed only in such a case.

  First, when shifting is performed (step ST1), when connection / disconnection switching of the clutches 801, 802, 803, 804, 805, 806 is started (step ST2), as described above, the clutches 801, 802, 803, 804, 805 are performed. , 806 is calculated. When the heat generation amount exceeds a predetermined threshold (step ST4), a process for increasing the hydraulic pressure for operating the clutches 801, 802, 803, 804, 805, 806 is performed (step ST5), and the torque of the internal combustion engine is reduced. (Step ST6). In this way, the connection / disconnection switching of the clutches 801, 802, 803, 804, 805, 806 is completed more quickly than when the heat generation amount does not exceed the threshold (step ST7).

  As described above, the ECU 0 serving as the transmission control device according to the present embodiment requires the time required for switching between connection and disconnection of 801, 802, 803, 804, 805, and 806 when the amount of heat generation exceeds a predetermined threshold, that is, heat generation. The amount of heat generated is prevented from increasing by shortening the time during which the so-called half-clutch state occurs. As a result, the amount of heat generation can be suppressed while avoiding increasing the number and area of 801, 802, 803, 804, 805, 806 itself, and as a result, the durability of 801, 802, 803, 804, 805, 806 is effective. It has been improved.

  Although the embodiment of the present invention has been described above, the specific configuration of each unit is not limited to the above-described embodiment, and various modifications can be made without departing from the spirit of the present invention.

  For example, in the above embodiment, the aspect in which the present invention is applied to the clutch of the stepped transmission is disclosed. Of course, the present invention is applied to a continuously variable transmission called CVT or a manual transmission, that is, a manual transmission. The invention may be applied. When a continuously variable transmission is applied, the shift clutch mounted on the forward / reverse switching device connected to the continuously variable transmission is used. When a manual transmission is applied, the clutch that is connected / disconnected by depression of the clutch pedal is the main clutch. It corresponds to the clutch of the invention. Further, specific modes of the internal combustion engine and specific modes such as control of the rotational speed are not limited to those of the above-described embodiment, and various modes including the existing ones can be applied. .

  In addition, the specific configuration of each part is not limited to the above embodiment, and various modifications can be made without departing from the spirit of the present invention.

  The present invention can be used as a control device for a transmission that is mounted on a vehicle and performs a shift automatically or manually.

8 ... Transmission (stepped transmission)
801 ... Clutch (reverse clutch)
802 ... Clutch (forward clutch)
803 ... Clutch (rear clutch)
804 ... Clutch (one-way clutch)
805 ... Clutch (2 & 4 brake)
806 ... Clutch (1 & reverse brake)
0 ... Transmission control unit (ECU)

Claims (1)

A control device for a transmission that switches connection / disconnection of a clutch at the time of shifting,
Calculate the amount of heat generated during clutch connection / disconnection switching,
A transmission control device for performing a switching time shortening process for shortening a time required for switching between connection and disconnection of a clutch when the heat generation amount exceeds a predetermined threshold value.

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