JP2005273828A - Gear transmission - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a gear transmission, in which generation of idling noise can be prevented in all the driving ranges even in a case where variation width of rotation resistance inputted to the input shaft side by oil temperature fluctuation or product tolerance or the like is relatively large. <P>SOLUTION: This gear transmission is provided with an input shaft 4 integrally comprising an input gear 8 to which power from an engine 1 is inputted through a clutch 5, a counter shaft 11 integrally comprising a counter shaft drive gear 10 to be engaged with the input gear 8 and stored in a transmission 3 with relation to the input shaft 4, a mechanical brake means 25 to add rotation resistance to the counter shaft 11, an oil temperature detecting means 26 to detect temperature of oil in the transmission, an engine rotation detecting means to detect rotation of the engine 1, and a control means to add the rotation resistance from the mechanical brake means 25 to the counter shaft 11 when the engine 1 is in a prescribed low rotation range, and as the oil temperature is in a prescribed temperature range. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a technique for preventing idle noise generated due to backlash between a plurality of gears provided on an input shaft and a countershaft in a gear transmission provided in an engine drive system of a vehicle.

  In a gear transmission provided in an engine drive system of a vehicle, when the engine is idling with the gear shift position as a neutral position, abnormal noise, so-called idle noise, is generated from the vicinity of the gear transmission to which rotation is transmitted via a clutch. Sometimes.

  The idle noise of this gear transmission is generated when the gear meshing portion in the transmission is relatively displaced within the backlash range due to torsional vibration caused by engine rotation angle fluctuation and torque fluctuation during idling operation. The engine rotation angle fluctuation transmitted to the transmission through the clutch causes separation within the range of backlash between the gears that have been pressed against each other by overcoming the input rotation resistance such as sliding resistance and oil viscosity. This is caused by abnormal noise generated by the gears striking each other. Further, as shown in FIG. 5, the rotational resistance (%) from the counter shaft and the main shaft that is input to the input shaft of the clutch can be reduced as the oil temperature (° C.) in the gear transmission increases. Are known.

  Incidentally, as shown in FIGS. 2A and 2B, for example, the ordinary clutch disk 5 is integrated by an inner plate 5A integrated with the boss 5Aa and a pin 5F so as to sandwich the inner plate 5A. The outer plates 5B, 5C and the facing plates 5D, 5E integrated with the outer plates 5B, 5C and the pins (not shown), and the spring receiving holes 5Ab, 5Ba, 5Ca formed in the inner plate 5A and the outer plates 5B, 5C, respectively. And a damper spring 5G to be fitted to the. The inner plate 5A is formed with four notches 5Ac that avoid the pins 5F, and the inner plate 5A and the outer plates 5B, 5C can rotate relative to each other within the range S between the notches 5Ac and the pins 5F. It is configured. The clutch disc 5 performs a damper operation that absorbs this rotational angular displacement by compressing and deforming each damper spring 5G according to the rotational angular displacement between the inner plate 5A and the outer plates 5B and 55C.

  As shown in FIG. 5, a damper operation that absorbs fluctuations in the relative rotation angle of the inner plate 5A (gear transmission side) with respect to the outer plates 5B and 5C (engine flywheel side) by a damper spring 5G having a predetermined spring constant. The possible range En is affected by the magnitude of the input rotational resistance input to the damper spring 5G, and this input rotational resistance varies depending on the oil temperature level which is correlated with the oil viscosity.

  Since the idle noise in the transmission is correlated with the oil temperature in the transmission in addition to the spring constant of the damper spring, when the oil temperature is in the normal operating temperature range, the idle noise is minimized. Various conditions of the transmission such as the spring constant and hysteresis of the damper spring, the backlash amount of the gear meshing portion, and the rotation resistance are set. Thereby, the rotation angle-torsion torque characteristic of the clutch shown in FIG. 6 is determined.

  Taking into account the rotational angle-torsional torque characteristics of the clutch as described above, the range of fluctuations in the input rotational resistance applied to the input shaft is taken into account, and in accordance with the fluctuation range of this input rotational resistance. The clutch damper operable area En is set so as to overlap the temperature range of the oil temperature during normal use.

  In order to prevent idle noise from the gear transmission, a method for mechanically reducing backlash between the top gear of the gear transmission and the countershaft drive gear is known. A technique for eliminating backlash by disposing an annular elastic body on the same axis of each gear and meshing and rotating the gears in a state where the elastic bodies are in pressure contact with each other is disclosed in, for example, “Patent Document 1”. It is disclosed. Further, a technique for connecting and disconnecting the brake disc on the countershaft side with a hydraulic piston and applying a braking force to the countershaft at the first speed or the reverse stage to prevent noise generation at a low speed is, for example, “ Patent Document 2 ”discloses.

Japanese Patent Laid-Open No. 10-38054 Japanese Patent Publication No. 4-81068

  As described above, the damper operable range En included in the damper spring of the clutch is set so as to cover the fluctuation range of the input rotation resistance when the oil temperature is in the normal operating temperature range (for example, 15 ° C. or higher). However, when the oil temperature is in a low temperature range that deviates from the temperature range during normal use as in the Ec range shown in FIG. 5, the fluctuation range of the input rotational resistance deviates from the damper operable range En and the gear transmission idles. Noise cannot be prevented.

  When the fluctuation range of the input rotation resistance is large as described above, or when the fluctuation range of the input rotation resistance is shifted due to a product error, this cannot be completely covered by the damper operable area En included in the damper spring of the clutch. When the oil temperature is operated in the low temperature range Ec corresponding to the fluctuation range of the input rotational resistance that cannot be covered, idle noise is generated from the gear transmission, and improvement thereof is desired.

  The present invention solves the above-mentioned problems, and even when the fluctuation range of the rotational resistance input to the input shaft side is relatively large due to oil temperature fluctuations, product errors, etc., the generation of idle noise can be achieved in the entire operating range. An object of the present invention is to provide a gear transmission that can be prevented.

  According to a first aspect of the present invention, there is provided an input shaft that is integrally provided with an input gear and that receives power from an engine via a clutch, and the input gear that is housed in a transmission in association with the input shaft. A countershaft integrally having a countershaft drive gear that meshes, a rotation resistance adding means for adding a rotation resistance to the countershaft, an oil temperature detecting means for detecting the temperature of oil in the transmission, and the rotation of the engine Engine rotational speed detecting means for detecting the number, and control means for adding rotational resistance from the rotational resistance adding means to the countershaft when the engine is in a predetermined low rotational range and the oil temperature is in a predetermined temperature range; A gear transmission comprising: mechanical braking means as the rotation resistance adding means.

  According to a second aspect of the present invention, in the gear transmission according to the first aspect of the invention, the damper spring is operable to absorb a fluctuation in a rotation angle on the input shaft side with respect to the engine flywheel according to the damper spring of the clutch. A damper operable range is set, and the predetermined temperature range is set as a temperature range corresponding to a low rotation resistance range lower than a lower limit value of the damper operable range.

  According to a third aspect of the present invention, in the gear transmission according to the first or second aspect, the counter shaft integrally includes a rotating member, and the mechanical braking means brakes the rotating member by friction. It is a friction brake.

  According to a fourth aspect of the present invention, in the gear transmission according to the third aspect, the friction brake is operated by a fluid pressure.

  According to a fifth aspect of the present invention, in the gear transmission according to the third aspect, the friction brake is further electrically operated.

  According to the present invention, when the engine speed is in the predetermined low rotation range and the oil temperature is in the predetermined temperature range, the rotational resistance from the mechanical braking means is added to the countershaft and the input rotation applied to the input shaft. As the resistance is increased, the input rotational resistance applied to the input shaft is adjusted so that it enters the damper operable range of the damper spring of the clutch disk even in the predetermined temperature range, and the damper spring reduces the input rotational resistance even in the predetermined temperature range. The damper operates to absorb it, and the generation of idle noise can be prevented.

  FIG. 1 shows an embodiment of the present invention. In the same figure, the code | symbol 1 has shown the engine output shaft, The flywheel 2 is attached to the edge part. The gear transmission 3 is disposed on the right side of the flywheel 2, and a clutch disk 5 attached to the input shaft 4 of the gear transmission 3 is disposed at a portion corresponding to the flywheel 2.

  An input gear 8 is integrally attached to an input shaft 4 whose one end is rotatably supported by a casing 7 by a bearing 6, and below that both ends are rotatably supported by the casing 7 by a bearing 9. A counter shaft 11 having a counter shaft drive gear 10 that meshes with the input gear 8 is integrally provided at one end thereof. In addition to the countershaft drive gear 10, countershaft gears 12, 13, 14, and 15 having different diameters are integrally provided on the countershaft 11, respectively.

  On the right side of the input shaft 4, it is arranged coaxially with the input shaft 4, one end of which is rotatably supported by the casing 7 by the bearing 6 and the other end of the input shaft 4 by the bearing 23. An individually rotatable main shaft 16 is disposed. The main shaft 16 meshes with the fourth speed gear 17 that meshes with the countershaft gear 12, the third speed gear 18 that meshes with the countershaft gear 13, the second speed gear 19 that meshes with the countershaft gear 14, and the countershaft gear 15. The first speed gears 20 are disposed, and the gears 17, 18, 19, and 20 are rotatably supported with respect to the main shaft 16.

  An appropriate amount of oil to be supplied to the gears 8, 10, 12, 13, 14, 15, 17, 18, 19, and 20 is placed inside the casing 7, and the oil is rotated according to the rotation of the gears. Splashed on the gear. An oil temperature detecting means 26 comprising a thermometer or a thermocouple for detecting the temperature of the oil in the casing 7 is disposed inside the casing 7 where oil is stored.

  A synchronization device 21 is disposed between the fourth speed gear 17 and the third speed gear 18, and a synchronization device 22 is disposed between the second speed gear 19 and the first speed gear 20. Each of the synchronization devices 21 and 22 has a known configuration including a sleeve, a synchronizer ring, and the like, and either one of the gears 17 and 18 is activated when the synchronization device 21 is operated, and each gear is operated when the synchronization device 22 is operated. Any one of 19 and 20 is configured to be integrated with the main shaft 16. Only one of the synchronizers 21 and 22 is selectively operated.

  The clutch disk 5 shown in FIG. 2 is used, and when the clutch disk 5 is connected to the flywheel 2, the damper spring 5G contracts to cause the clutch disk 5 and the input shaft 4 to The relative rotation of the engine and the rotational force from the engine output shaft 1 abruptly transmitted to the input shaft 4 can be mitigated to prevent the occurrence of noise due to gear rattling caused by engine rotation fluctuations during idling. In addition, the deterioration of riding comfort due to the rapid transmission of engine rotation is prevented.

  The other end of the counter shaft 11 protrudes from the casing 7, and a disk 24 as a rotating member is integrally attached to the tip of the counter shaft 11. In the vicinity of the disc 24, as shown in FIG. 1, a mechanical braking means that selectively occupies a position spaced from the disc 24 and a position in contact with the disc 24 and applies a braking force to the disc 24. A friction brake 25 is provided. In this embodiment, the friction brake 25 is operated by an actuator that is operated by fluid pressure such as a hydraulic cylinder or a pneumatic cylinder, and applies a predetermined braking force to the disc 24. This actuator is connected to a controller (not shown) as control means. Note that the friction brake 25 may be one that is actuated by an electrically actuated actuator such as a solenoid and applies a predetermined braking force to the disc 24.

  Here, the input rotational resistance value applied to the input shaft 4 of the gear transmission 3, that is, the damper spring 5 G of the clutch disk 5 exhibits a fluctuation characteristic as shown by a solid line in FIG. 3, and the oil temperature in the casing 7 is 20 ° C. If it exceeds, the input rotation resistance value will deviate from the damper operable range En in which the damper spring 5G can absorb the fluctuation of the rotation angle of the flywheel 2 on the input shaft 4 side.

  However, here, based on this characteristic, if the oil temperature is in a predetermined low rotation range and the oil temperature is in a temperature range exceeding 20 ° C., which is the predetermined temperature range, the controller operates the actuator and the friction brake 25 applies the disc 24 to the disc 24. On the other hand, control is performed so as to apply a predetermined braking force. As a result, in an operating range where the oil temperature exceeds 20 ° C., rotational resistance due to the operation of the friction brake 25 is added to the countershaft 11, and the input rotational resistance applied to the input shaft 4 increases as shown by a broken line in FIG. Is done. As a result, even in the operating range where the oil temperature exceeds 20 ° C., the input rotational resistance applied to the input shaft 4 is adjusted so as to enter the damper operable range En of the damper spring 5G of the clutch disk 5, and the oil temperature exceeds 20 ° C. Even in the operating range, the damper spring 5G operates as a damper so as to absorb the input rotation resistance, thereby preventing the generation of idle noise.

  The controller takes in the oil temperature in the casing 7 detected by the oil temperature detecting means 26, takes in the engine speed detected by the engine speed detecting means (not shown), and adds rotational resistance based on these detection results. Take control. The controller has a rotation resistance addition control function of operating the friction brake 25 and adding a rotation resistance to the counter shaft 11 when the engine is in a predetermined low rotation range and the oil temperature is in a predetermined temperature range. Therefore, rotation resistance addition control as shown in FIG. 4 is executed. The rotation resistance addition control process for the gear transmission 3 performed by this controller will be described with reference to FIG.

  When the main switch (not shown) is turned on and the process reaches step s1, the controller takes in the data of the engine speed Ne and the oil temperature Tm, performs a predetermined storage process, and then proceeds to step s2. In step s2, it is determined whether or not the engine speed Ne is within a predetermined low rotation range that is greater than the cranking determination value Nec and less than or equal to a predetermined low rotation determination value Nea. To do. If it is within the predetermined low speed range, the process proceeds to step s3 to determine whether or not the oil temperature Tm exceeds 20 ° C. If the oil temperature is below 20 ° C, the control is terminated and exceeds 20 ° C. If YES, go to step s4.

  Note that, in a predetermined low rotation range where the oil temperature Tm is 20 ° C. or less, the input rotation resistance is transmitted from the counter shaft 11 to the input shaft 4 side along the fluctuation characteristics shown by the solid line in FIG. Since the value enters the damper operable range En of the damper spring 5G, the damper spring 5G reliably operates the damper so that the input rotational resistance is absorbed and the generation of idle noise is prevented.

  When step s4 is reached, the controller operates the actuator because the current situation is the predetermined low speed range and the oil temperature is in the operating range above 20 ° C. As a result, the friction brake 25 is operated, and the rotational resistance due to the operation of the friction brake 25 is transmitted to the input shaft 4 side via the disk 24 and the countershaft 11, and the rotational resistance received by the input shaft 4 exceeds the oil temperature of 20 ° C. Even in the operation region, the damper spring 5G enters the damper operable region En, and the damper spring 5G reliably operates to absorb the input rotational resistance, thereby preventing the generation of idle noise.

  As described above, when the input rotational resistance corresponding to the oil temperature-input rotational resistance characteristic curve shown in FIG. 3 is applied to the damper spring 5G of the clutch disk 5, the rotational resistance input to the input shaft 4 side due to product error or the like. Even when the fluctuation range is relatively large, when the oil temperature enters a predetermined temperature range exceeding 20 ° C., the controller operates the actuator, and the rotational resistance due to the operation of the friction brake 25 is reduced to the disc 24 and the counter shaft 11. To the input shaft 4 side, the input rotational resistance is raised, and processing is performed so that the raised input rotational resistance enters the damper operable region En of the damper spring 5G. For this reason, even if the oil temperature enters a predetermined temperature range where the temperature exceeds 20 ° C. and the input rotational resistance applied to the input shaft 4 is reduced, the damper spring 5G operates in the damper operable range En, and the damper operates. The rattling between the gear 8 and the countershaft drive gear 10 can be reduced to prevent the generation of idle noise.

  In the above-described embodiment, the damper operating range En is set so that the damper spring 5G can absorb the input rotation resistance when the oil temperature exceeds 20 ° C. Is appropriately set according to the region where the vehicle normally travels, and the damper operable region En is also appropriately corrected according to the fluctuation characteristics of the input rotational resistance corresponding to the oil temperature.

  In the rotation resistance addition control process of the above-described embodiment, it is determined whether or not the engine speed Ne is within a predetermined low rotation range that is greater than the cranking determination value Nec and less than or equal to the predetermined low rotation determination value Nea. The predetermined low rotation range is not limited to the idle rotation range, but includes a low rotation range during low-speed traveling.

  In the above-described embodiment, an example in which the input shaft 4 and the main shaft 16 are arranged in series on the same axis as the gear transmission 3 has been described. However, the counter shaft 11 and the main shaft 16 are sequentially spaced from the input shaft 4 at predetermined intervals. The present invention can also be applied to a gear transmission that employs another gear arrangement configuration such as being arranged in parallel.

It is a schematic block diagram of the gear transmission which employ | adopted one Embodiment of this invention. It is (a) sectional drawing (b) front view of the clutch disc used for one Embodiment of this invention, and a prior art. It is a diagram which shows the fluctuation characteristic with respect to the oil temperature of the input rotational resistance added to the damper spring of the clutch disk in one Embodiment of this invention. It is a flowchart of the rotation resistance addition control process in one Embodiment of this invention. It is a diagram which shows the fluctuation characteristic with respect to the oil temperature of the input rotational resistance added to the damper spring of the clutch disk for demonstrating the conventional problem. It is a diagram which shows the rotation angle-torsion torque characteristic of the conventional clutch.

Explanation of symbols

1 Engine (engine output shaft)
2 Engine flywheel (flywheel)
3. Transmission (gear transmission)
4 Input shaft 5 Clutch (clutch disc)
5G damper spring 8 input gear 10 counter shaft drive gear 11 counter shaft 24 rotating member (disk)
25 Mechanical braking means (friction brake)
26 Oil temperature detection means En Damper operable range

Claims (5)

An input shaft which has an input gear integrally and receives power from the engine via a clutch;
A countershaft integrally having a countershaft drive gear meshed with the input gear, housed in a transmission in association with the input shaft;
Rotation resistance adding means for adding rotation resistance to the countershaft;
Oil temperature detecting means for detecting the temperature of oil in the transmission;
Engine speed detecting means for detecting the engine speed;
A gear transmission comprising: control means for adding rotational resistance from the rotational resistance adding means to the counter shaft when the engine is in a predetermined low rotational range and the oil temperature is in a predetermined temperature range;
A gear transmission using mechanical braking means as the rotation resistance adding means. The gear transmission according to claim 1, wherein
In accordance with the damper spring of the clutch, a damper operable region in which the damper spring can operate to absorb fluctuations in the rotation angle on the input shaft side with respect to the engine flywheel is set, and the predetermined temperature region is the damper operable region A gear transmission, characterized in that it is set as a temperature range corresponding to a low rotational resistance range below a lower limit value of. The gear transmission according to claim 1 or 2,
The gear transmission according to claim 1, wherein the counter shaft integrally includes a rotating member, and the mechanical braking means is a friction brake that brakes the rotating member by friction. The gear transmission according to claim 3, wherein
The gear transmission, wherein the friction brake is operated by fluid pressure. The gear transmission according to claim 3, wherein
The gear transmission is characterized in that the friction brake is electrically operated.

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