JP2012107659A - Control device of friction clutch for vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide the control device of a friction clutch for a vehicle which can obtain a clamp point to be a reference with high precision when controlling the friction clutch.SOLUTION: When it is determined that the clutch temperature thc of an automatic clutch 14 is stable, the correction lower limit reference value clampmin and the correction upper limit reference value clampmax are set with the clamp point clamps learned in this situation as the reference value. Accordingly, since the correction lower limit reference value clampmin and the correction upper limit reference value clampmax for regulating the range of the possible value of the clamp point clamp at the correction are set with the clamp point clamps learned when the clutch temperature thc is stable as the reference value, excessive correction of the clamp point clamp is prevented, and further, divergence of the clamp point clamp occurring when heat generation and heat radiation are repeated in an automatic clutch 14, can be prevented.

Description

  The present invention relates to a friction clutch control device provided in a vehicle, and more particularly to a technique for improving the controllability of a friction clutch.

  2. Description of the Related Art In a power transmission path from a driving source such as an engine to driving wheels, a friction clutch for selectively interrupting the power transmission path via an actuator is known. For example, a clutch control device described in Patent Document 1 is an example. Patent Document 1 discloses a technique for detecting the surface temperature of the clutch disk 21a and correcting the control amount of the friction clutch 21 based on the detected surface temperature. By correcting as described above, the clutch torque is suitably controlled in consideration of the thermal expansion of the components of the clutch.

JP 2008-185217 A

  By the way, in order to control the friction clutch with high accuracy, it is necessary to successively grasp the clamp point of the friction clutch with high accuracy. Here, the clamp point of the friction clutch is a point at which the friction clutch is completely engaged, and the friction clutch is controlled with reference to the clamp point. As described above, Patent Document 1 is a technique for correcting the control amount of the clutch stroke based on the surface temperature of the clutch disk 21a. In practice, the clamp point of the friction clutch is used as the surface temperature of the clutch disk 21a. It corresponds to correcting based on. As described above, although the controllability of the friction clutch is improved only by correcting the clamp point based on the surface temperature of the clutch disk 21a, it cannot always be said that the correction is sufficiently accurate. For example, the change point of the friction clutch clamp point differs between the heat generation side and the heat dissipation side of the friction clutch. Therefore, although not known, a method of switching the calculation method of the clamp point of the friction clutch between the heat generation side and the heat dissipation side has been devised. As described above, the clamp point can be calculated with higher accuracy by switching the calculation method of the clamp point according to either heat generation or heat dissipation of the friction clutch. However, as described above, the change characteristic of the clamp point changes between the heat generation side and the heat dissipation side of the friction clutch, that is, the coefficient of thermal expansion of the friction clutch takes a different value between the heat generation side and the heat dissipation side. If heat generation and heat dissipation are repeated, overcorrection of the clamp point occurs, and the temperature correction value of the clamp point may diverge on the increase side or the decrease side.

  The present invention has been made against the background of the above circumstances, and an object of the present invention is to accurately obtain a reference clamp point when controlling a friction clutch in a friction clutch provided in a vehicle. The object is to provide a control device for a friction clutch for a vehicle.

  In order to achieve the above object, the gist of the invention according to claim 1 is that: (a) In a friction clutch for a vehicle controlled by an actuator, a clamp point at which the friction clutch is completely engaged is defined as the friction clutch. And a friction clutch control device for a vehicle that controls the friction clutch based on the corrected clamp point, and (b) when the clutch temperature of the friction clutch is stable. A correction lower limit reference value and a correction upper limit reference value that define a range of values that can be taken by the clamp point at the time of correction are set with the clamp point learned as a reference value.

  According to a second aspect of the present invention, there is provided a vehicular friction clutch control device according to the first aspect, wherein: (a) the friction clutch is housed in a clutch case fixed to an engine. A dry clutch that is adjacent to the engine and selectively interrupts the power transmission path between the crankshaft of the engine and the transmission, and (b) the clutch temperature of the friction clutch When in the vicinity, the clutch temperature of the friction clutch is determined to be stable.

  According to a third aspect of the present invention, there is provided a vehicular friction clutch control device according to the first aspect, wherein: (a) the friction clutch is disposed adjacent to a transmission; (b) The clutch temperature of the friction clutch is determined to be stable when the clutch temperature of the friction clutch is close to the hydraulic oil temperature of the transmission.

  According to a fourth aspect of the present invention, in the vehicle friction clutch according to any one of the first to third aspects, the correction lower limit reference value is obtained when the clutch temperature of the friction clutch is stable. The correction upper limit reference value is calculated by adding a predetermined value set in advance to the correction lower limit reference value.

  According to a fifth aspect of the present invention, there is provided the vehicle friction clutch control device according to the fifth aspect, wherein the predetermined value is a predetermined constant value or the predetermined friction value. The value is determined based on a relationship map between the clutch temperature and the clamp point of the clutch.

  According to a sixth aspect of the present invention, there is provided a vehicular friction clutch control device according to any one of the first to fifth aspects, wherein (a) the clutch temperature is not stable, and When the clamp point learned at that time falls below the correction lower limit reference value, the clamp point is reset to the correction lower limit reference value, and (b) the clutch temperature is not stable. In addition, when the clamp point learned at that time exceeds the correction upper limit reference value, the clamp point is reset to the correction upper limit reference value.

  According to the control apparatus for a friction clutch for a vehicle of the invention according to claim 1, the correction lower limit reference value and the correction upper limit reference value with the clamp point learned when the clutch temperature of the friction clutch is stable as a reference value. Is set. In this way, with the clamp point learned when the clutch temperature is stable as the reference value, the correction lower limit reference value and the correction upper limit reference value that define the range of values that the clamp point can take are set by correction. Therefore, overcorrection of the clamp point is prevented, and divergence of the clamp point that occurs when heat generation and heat dissipation are repeated in the friction clutch can be prevented.

  According to the vehicle friction clutch control device of the invention of claim 2, when the clutch temperature of the friction clutch is in the vicinity of the engine coolant temperature of the engine coolant, it is determined that the clutch temperature of the friction clutch is stable. Is done. The friction clutch is an automatic clutch that is adjacent to the engine in a state of being accommodated in a clutch case fixed to the engine, and selectively interrupts the power transmission path between the engine crankshaft and the transmission. When there is no heat generation or heat dissipation in the friction clutch, the clutch temperature converges to the engine temperature, that is, the engine water temperature. Therefore, when the clutch temperature reaches a temperature close to the engine water temperature, the clutch temperature is stable, and further contraction of the friction clutch does not substantially occur. By setting the value and the correction upper limit reference value, the optimum correction lower limit reference value and correction upper limit reference value can be obtained.

  According to the control apparatus for a vehicle friction clutch of the invention according to claim 3, the friction clutch is disposed adjacent to the transmission, and the clutch temperature of the friction clutch is the hydraulic oil temperature of the transmission. When in the vicinity, it is determined that the clutch temperature of the friction clutch is stable. When the friction clutch is disposed adjacent to the transmission, the clutch temperature converges to the hydraulic oil temperature of the transmission when there is no heat generation or heat dissipation in the friction clutch. Therefore, when the clutch temperature reaches a temperature close to the hydraulic oil temperature of the transmission, the clutch temperature is stable and further contraction of the friction clutch does not substantially occur. By setting the correction lower limit reference value and the correction upper limit reference value, the optimum correction lower limit reference value and correction upper limit reference value can be obtained.

  According to the control apparatus for a vehicle friction clutch of the invention according to claim 4, the correction lower limit reference value is the clamp point learned when the clutch temperature of the friction clutch is stable, The correction upper limit reference value is calculated by adding a predetermined value set in advance to the correction lower limit reference value. In this way, it is possible to set the optimum correction lower limit reference value and correction upper limit reference value in a state where the clutch temperature of the friction clutch is stable.

  According to the control device for a friction clutch for a vehicle of the invention according to claim 5, the predetermined value is a preset constant value, or a preset clutch temperature and clamp point of the friction clutch. This value is determined based on the relationship map. In this way, the optimum correction upper limit reference value can be set based on the determined predetermined value.

  According to the control apparatus for a vehicle friction clutch of the invention according to claim 6, when the clutch temperature is not stable, and the clamp point learned at that time is the correction lower limit reference value. The clamp point is reset to the correction lower-limit reference value, the clutch temperature is not stable, and the clamp point learned at that time is equal to the correction upper-limit reference value. If it exceeds, the clamp point is reset to the correction upper limit reference value. By doing this, it is possible to secure a region where a minimum necessary clamp point can be taken while absorbing variations in stroke sensors and errors in the estimated value of the clutch temperature.

1 is a skeleton diagram illustrating a schematic configuration of a vehicle drive device to which the present invention is applied. It is a figure explaining the control structure for controlling the automatic clutch of FIG. FIG. 2 is a diagram showing a relationship between a clutch stroke and a clutch torque capacity in the automatic clutch of FIG. 1. It is a figure which shows the positional relationship of the clamp point with respect to the clutch temperature of the automatic clutch shown in FIG. It is a functional block diagram for demonstrating the principal part of control action of the electronic controller of FIG. It is an example of the relationship map of the correction coefficient set according to a refrigerant temperature. It is a relationship map of clutch temperature and a clamp point. The flowchart for explaining the control operation that can improve the controllability of the automatic clutch by correcting the clamp point according to the main part of the control operation of the electronic control unit, that is, the heat generation and heat dissipation of the automatic clutch. is there. It is a flowchart for demonstrating the control operation | movement which sets the correction | amendment upper limit reference value of a clamp point, and a correction | amendment lower limit reference value in the principal part of the control action of an electronic controller, ie, the learning control of a clamp point. It is a skeleton diagram explaining the schematic structure of the vehicle drive device which is the other Example of this invention.

  Here, preferably, the clutch temperature of the friction clutch corresponds to the surface temperature of the clutch disk constituting the friction clutch, and the temperature is detected by a temperature sensor or calculation.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In the following embodiments, the drawings are appropriately simplified or modified, and the dimensional ratios, shapes, and the like of the respective parts are not necessarily drawn accurately.

  FIG. 1 is a skeleton diagram illustrating a schematic configuration of a vehicle drive device 10 to which the present invention is applied. FIG. 2 is a diagram schematically illustrating a control configuration for controlling the automatic clutch 14 of FIG. It is. As shown in FIG. 1, the vehicle drive device 10 is for a FR (front engine / rear drive) vehicle, for example, and includes an engine 12 as a travel drive source, and an automatic clutch 14. This is an automatic manual transmission (MT) equipped with a vehicle transmission 16 and the like.

  The vehicle transmission 16 is a constant-mesh parallel twin-shaft transmission, and when a shift command to a predetermined shift stage is output based on a preset shift map, the predetermined shift stage is It is configured to be established.

  The automatic clutch 14 corresponding to the vehicle friction clutch of the present invention is housed in a clutch case 15 having one axial end fixed to the engine 12 and the other fixed to the vehicle transmission 16. In the state, it is disposed adjacent to the engine 12. The automatic clutch 14 is a dry single-plate friction clutch, a flywheel 22 attached to the crankshaft 20 of the engine 12, a clutch disk 26 connected to the clutch output shaft 24, and a pressure plate 30 provided on the clutch cover 28. A diaphragm spring 32, a hydraulic clutch release cylinder 34, and a clutch fork cylinder 34 are connected via a release fork 36 by energizing the pressure plate 30 toward the flywheel 22 to pinch the clutch disk 26 to transmit power. Is moved to the flywheel 22 side (right side in the figure) to displace the inner end of the diaphragm spring 32 to the flywheel 22 side (right side in the figure) to release (disconnect) the automatic clutch 14. And it is configured with a Zusuribu 38.

  For example, in a state where hydraulic oil is not supplied into the hydraulic chamber of the clutch release cylinder 34, the automatic clutch 14 is connected as the pressure plate 30 presses the clutch disk 26 by the urging force of the diaphragm spring 32. When hydraulic oil is supplied into the hydraulic chamber of the clutch release cylinder 34, the piston 40 driven by the hydraulic oil moves, and the release sleeve 38 is moved to the flywheel 22 side (right side in the drawing) via the release fork 36. The release sleeve 38 presses the inner peripheral end of the diaphragm spring 32. Accordingly, since the urging force of the diaphragm spring 32 is reduced, the force with which the pressure plate 30 presses the clutch disk 26 is weakened, and the torque capacity of the automatic clutch 14 is reduced. When the movement position (clutch stroke position clts) of the release sleeve 38 reaches a predetermined amount, the pressure plate 30 does not press the clutch disk 26 and the automatic clutch 14 is released. The movement position (clutch stroke position clts) of the release sleeve 38 is controlled by controlling the amount of hydraulic oil supplied to the clutch release cylinder 34.

  The electronic control unit 44 includes a microcomputer, and performs signal processing in accordance with a program stored in advance in the ROM while using a temporary storage function of the RAM. The electronic control unit 44 includes a signal representing the engine rotational speed Ne from the engine rotational speed sensor 46, a signal representing the rotational speed of the clutch output shaft 24 (output shaft rotational speed Nc) from the clutch output shaft rotational speed sensor 48, and opening of the throttle valve. A signal representing the throttle valve opening θth from the degree sensor 50, a signal representing the refrigerant temperature thr of the automatic clutch 14 from the refrigerant temperature detection sensor 52, that is, a signal representing the outside air temperature (atmosphere temperature) thr for cooling the automatic clutch 14, And a signal representing the engine coolant temperature Tw of the engine coolant from the engine coolant temperature sensor 56 are supplied. A signal representing a vehicle speed V from a vehicle speed sensor (not shown); a signal representing an intake air amount Q from an intake air amount sensor; a signal representing a lever position from a lever position sensor; a signal representing an accelerator opening Acc from an accelerator opening sensor; A signal indicating ON / OFF of the foot brake is supplied from the brake switch. The clutch stroke sensor 54 is a sensor that detects the movement position of the release sleeve 38. In this embodiment, the movement position of the release sleeve 38 from a clamp point clamp described later is defined as a clutch stroke position clts.

  Then, in accordance with the signal, the electronic control unit 44 controls the fuel injection amount and injection timing of a fuel injection valve (not shown) of the engine 12, controls the ignition timing of a spark plug with an igniter (not shown), The output state of the engine 12 is controlled by opening and closing the opening degree θth of the electronic throttle valve by a throttle actuator. Further, the electronic control unit 44 controls the shift control of the vehicle transmission 16 according to the running state and the on / off state of the automatic clutch 14 during the shift control. Note that the control of the on / off state of the automatic clutch 14 is performed by hydraulic control of hydraulic oil supplied to the clutch release cylinder 34. The hydraulic pressure of the hydraulic oil supplied to the clutch release cylinder 34 is configured to be controllable by a linear solenoid valve 58, and the electronic control unit 44 controls the hydraulic pressure at the time of controlling the intermittent state of the automatic clutch 14 to the linear solenoid valve 58. Outputs a command. Note that the details of the hydraulic circuit including the linear solenoid valve 58 that controls the clutch release cylinder 34 are well known in the art and are omitted in FIG.

  By the way, when controlling the intermittent state of the automatic clutch 14, a clamp point clamp where the automatic clutch 14 is completely engaged and a touch point touch where the half engagement (slip engagement) of the automatic clutch 14 is started are required. Based on the determined clamp point clamp and touch point touch, the torque capacity of the automatic clutch 14 is controlled to change at a preset value. FIG. 3 shows the relationship between the clutch stroke position clts and the torque capacity Tc of the automatic clutch 14 obtained in advance through experiments or the like. When the clamp point clamp is set to the reference position (zero position in the figure) of the clutch stroke position clts, as the clutch stroke position clts increases, the urging force by the diaphragm spring 32 decreases and the pressure plate 30 presses the clutch disk 26. Since the force to perform becomes weak, the clutch torque capacity of the automatic clutch 14 gradually decreases. When the clutch stroke position clts reaches the touch point touch, the clutch torque capacity Tc becomes zero. Here, the clamp point clamp at which the automatic clutch 14 is completely engaged will be described in detail. When the hydraulic pressure of the clutch release cylinder 34 is released, the diaphragm spring 32 is restored to its original shape by its own elastic return force. This corresponds to the position of the release sleeve 38. Further, the touch point touch at which the half engagement (slip engagement) of the automatic clutch 14 is started will be described in detail. When the slip engagement is started, for example, when the connection of the automatic clutch 14 is started, the engine rotation speed is increased. This corresponds to the position of the release sleeve 38 when Ne changes.

  Here, paying attention to the clamp point clamp, the clamp point clamp changes in accordance with the surface temperature thc of the clutch disk 26 of the automatic clutch 14 (hereinafter referred to as clutch temperature thc). For example, when the clutch temperature thc of the clutch disk 26 increases, the clutch disk 26 expands, so that the thickness of the clutch disk 26 increases and the posture of the diaphragm spring 32 that contacts the outer peripheral side of the clutch disk 26 changes. Accordingly, the position of the release sleeve 38 that contacts the inner peripheral end of the diaphragm spring 32 changes, so that the clamp point clamp changes. On the other hand, the clutch temperature thc of the clutch disk 26 of the automatic clutch 14 is sequentially estimated, and the clamp point clamp is corrected based on the clutch temperature thc. However, there is a difference between when the clutch heat is generated and when the heat is dissipated, in which the thermal gradient in which the transient temperature change is dominant is large and in the situation in which the steady temperature change is the small thermal gradient. There are also differences in the state of the clutch cover 28 and the flywheel 22. Therefore, even at the same clutch temperature thc, there is a difference in the clamp point clamp between when the clutch generates heat and when it releases heat. FIG. 4 shows the position of the clamp point clamp with respect to the temperature thc (clutch temperature thc) of the clutch disk 26. As shown in FIG. 4, at the time of clutch expansion (heat generation) indicated by a solid line, for example, the clamp point clamp increases with a substantially constant gradient. On the other hand, when the clutch is contracted (during heat dissipation), it is discovered that a bending point is generated at the clamp point clamp, and the clamp point clamp is different between when the clutch is expanded and when the clutch is contracted even at the same clutch temperature thc. That is, the coefficient of thermal expansion of the clutch disk 26 differs between when the clutch is expanded and when it is contracted. Therefore, the electronic control unit 44 automatically increases the accuracy of the clamp point clamp by changing the correction amount of the clamp point clamp according to the temperature change direction of the clutch temperature thc of the clutch disk 26, that is, the clutch heat generation state / heat dissipation state. The control accuracy of the clutch 14 is improved.

  In addition, the amount of heat generated by the automatic clutch 14 and the amount of deformation of the clutch disk 26 associated therewith do not completely match the estimated value and the actual value. Because of the difference, if the heat generation and heat dissipation of the automatic clutch 14 are repeated when correcting the clamp point clamp, the temperature correction value of the clamp point clamp may diverge to the increase side or the decrease side. Therefore, the electronic control unit 44 sets the correction lower-limit reference value clampmin and the correction upper-limit reference value clampmax that define the range (region) of values that can be taken by the clamp point clamp obtained by the temperature correction of the clamp point. Prevent divergence of point clamp.

  FIG. 5 is a functional block diagram for explaining the main part of the control operation of the electronic control unit 44. In FIG. 5, each means surrounded by a one-dot chain line indicates a main function of the electronic control unit 44. The clutch control means 100 controls the clutch stroke position clts of the automatic clutch 14 (clutch on / off control) so that the automatic clutch 14 changes with the optimum torque capacity when the shift command of the vehicle transmission 16 is output. At this time, with reference to the clamp point clamp at which the automatic clutch 14 is completely engaged, the clutch stroke position clts from the clamp point clamp and the torque capacity Tc of the automatic clutch 14 are obtained and stored in advance as shown in FIG. Based on the relationship map, the clutch stroke clts is controlled so that the torque capacity Tc of the automatic clutch 14 changes suitably. In addition, high reproducibility is ensured because the clamp point in the fully engaged state of the automatic clutch 14 is used as a control reference.

  The clamp point correction unit 102 appropriately corrects a clamp point clamp that is a reference when the clutch control unit 100 is implemented according to the temperature change direction of the clutch temperature thc of the clutch disk 26. Here, the clutch temperature thc of the clutch disk 26 is sequentially estimated by the clutch temperature estimating means 104.

  The clutch temperature estimating means 104 is configured to detect the rotational speed Nc of the clutch output shaft 24 detected by the clutch output shaft rotational speed sensor 48 (hereinafter referred to as output shaft rotational speed Nc), the engine rotational speed Ne detected by the engine rotational speed sensor 46, The clutch temperature thc of the clutch disk 26 is calculated based on a known relationship stored in advance from the engine torque Te or the like. The engine torque Te is based on an engine torque map (two-dimensional map) configured from, for example, an engine rotation speed Ne and intake air amount (fuel injection amount) that are set and stored in advance. The engine torque Te is obtained from Ne and the intake air amount (fuel injection amount). Further, the engine torque Te may be directly detected by a torque sensor.

  When the clutch temperature thc of the clutch disk 26 is calculated, the clutch heat generation / radiation determination means 106 determines whether the clutch disk 26 is generating heat. The clutch heat generation / dissipation judging means 106 is a temperature difference Δthc (= thc−thcm) between the clutch temperature thc of the clutch disk 26 calculated by the clutch temperature estimating means 104 and the clutch temperature thcm of the clutch disk 26 calculated in the previous time step. ) Is calculated. If the calculated temperature difference Δthc is positive, it is determined that the temperature change direction of the clutch temperature thc of the clutch disk 26 is in the rising state (positive state), that is, the automatic clutch 14 is in the heat generating state. On the other hand, when the temperature Δthc is negative, it is determined that the temperature change direction of the clutch temperature thc of the clutch disk 26 is in the lowered state (negative state), that is, the clutch is in the heat dissipation state.

  When it is determined that the automatic clutch 14 is in a heat dissipation state, the clutch on / off determination means 108 determines whether or not the automatic clutch 14 is in a disconnected state (released state). The clutch on / off determination means 108 determines the on / off state of the automatic clutch 14 based on whether or not the clutch stroke position clts is larger than a preset touch point touch. For example, when the clutch stroke position clts is smaller than the touch point touch, it is determined that the automatic clutch 14 is connected (including half-engaged), that is, the automatic clutch 14 has a torque capacity Tc. On the other hand, when the clutch stroke position clts is larger than the touch point touch, it is determined that the automatic clutch 14 is disconnected, that is, the torque capacity Tc of the automatic clutch 14 is zero.

  When the clutch heat generation / dissipation determination means 106 determines whether the automatic clutch 14 is in a heat generation state or a heat dissipation state, and the clutch connection / disconnection determination means 108 determines the on / off state of the automatic clutch 14, the clamp point setting is performed. The means 102 sets a correction coefficient necessary for correcting the clamp point clamp according to the determination results. This correction coefficient is obtained from a relation map composed of the refrigerant temperature thr stored in the storage means 110. When the correction coefficient is changed according to the refrigerant temperature thr, the correction amount of the clamp point clamp is changed. In this embodiment, the above relationship map is obtained and stored separately when the automatic clutch 14 generates heat and when heat is released. When the automatic clutch 14 releases heat, the relationship map is displayed when the automatic clutch 14 is connected and disconnected. Furthermore, it is obtained separately and stored. That is, in this embodiment, three relationship maps are stored in the storage unit 110, and the correction coefficient is obtained based on the relationship map corresponding to the state of the automatic clutch 14.

  FIG. 6 shows an example of a relationship map of correction coefficients that change depending on the refrigerant temperature thr (for example, when the clutch generates heat). In FIG. 6, for example, when the refrigerant temperature thr becomes high, the correction coefficient increases. The relationship map is experimentally obtained in advance and is set so as to have a tendency that matches the physical phenomenon of the automatic clutch 14. Further, the correction coefficient may be obtained by precise calculation by thermal fluid analysis. Then, a correction coefficient for the estimated refrigerant temperature thr is obtained by an interpolation method or the like. The relationship map shown in FIG. 6 is experimentally obtained for each of the three modes of heat generation, heat dissipation (clutch disengagement), and heat dissipation (clutch engagement) of the automatic clutch 14. In FIG. 6, the correction coefficient increases as the refrigerant temperature thr increases. However, this is not necessarily the case in all clutches. FIG. 6 is an example, and the tendency and magnitude of the correction coefficient changes depending on various factors such as the structure of the clutch and the type of the vehicle. Therefore, whenever the structure of the clutch and the type of the vehicle change, the relationship map is tested each time. You have to ask for it.

The clamp point correction means 102 calculates the following equation (1) from the correction coefficient based on the relationship map according to the heat generation / heat dissipation state (that is, the temperature change direction) of the automatic clutch 14 and the on / off state of the automatic clutch 14 and the temperature change Δthc at that time. The clamp point clamp is calculated based on the following formula (3). The following formulas (1) to (3) are calculation formulas shown separately for each relationship map. Specifically, the expression (1) corresponds to a calculation expression for obtaining a clamp point clamp when the clutch heat is generated, that is, when the temperature is increased, and the expression (2) is when the clutch is radiated, that is, when the temperature is decreased. Corresponding to the calculation formula for obtaining the clamp point clamp at the time of disconnection, Equation (3) corresponds to the calculation formula for obtaining the clamp point clamp at the time of clutch heat dissipation (at the time of temperature drop) and at the time of clutch engagement. . In Expressions (1) to (3), clampm corresponds to the clamp point obtained in the previous time step, and Δthc represents the clutch temperature thc of the clutch disk 26 estimated this time and the clutch disk 26 estimated last time. Corresponds to the temperature difference (Δthc = thc−thcm) from the clutch temperature thcm, and Amap (thr) corresponds to the correction coefficient obtained from the relationship map used when the clutch heats up (when the clutch temperature rises). (thr) corresponds to the correction coefficient obtained when the clutch is dissipated (when the clutch temperature is lowered), and in particular the relationship map used when the clutch is disengaged, and B2map (thr) is when the clutch is dissipated (when the clutch temperature is lowered). In particular, it corresponds to the correction coefficient obtained by the relation map used when the clutch is engaged. In the equations (1) to (3), the second term on the right side corresponds to the correction amounts (Amap (thr) × Δthc, B1map (thr) × Δthc, B2map (thr) × Δthc). This correction amount is changed according to a change in the correction coefficient of the relation map. That is, the correction amount is changed in accordance with the heat generation / heat dissipation (temperature change direction) of the automatic clutch 14, the engaged / disengaged state of the clutch, and the refrigerant temperature thr.
clamp = clampm + Amap (thr) × Δthc (1)
clamp = clampm + B1map (thr) × Δthc (2)
clamp = clampm + B2map (thr) × Δthc (3)

  When the clamp point correction unit 102 calculates the clamp point clamp based on the equations (1) to (3), the calculated clamp point clamp is set in advance by an upper / lower limit reference value setting unit 114 described later. It is determined whether the clamp point clamp is out of the range of the correction upper limit reference value clampmax from the correction lower limit reference value clampmin by determining whether it is within the range between the correction lower limit reference value clampmin and the correction upper limit reference value clampmax. The clamp is corrected to the set correction upper limit reference value clampmax or the correction lower limit reference value clampmin. Specifically, when the corrected clamp point clamp falls below a preset correction lower limit reference value clampmin, the clamp point clamp is corrected to the correction lower limit reference value clampmin, and the corrected clamp point clamp is set in advance. When the correction upper limit reference value clampmax is exceeded, the clamp point clamp is corrected to the correction upper limit reference value clampmax. Accordingly, since the corrected clamp point clamp takes a value in the range of the corrected lower limit reference value clampmin to the corrected upper limit reference value clampmax, it is prevented that the clamp point clamp diverges in the increasing or decreasing direction.

  The clamp point learning unit 112 performs learning control of the clamp point clamp under a predetermined condition. Specifically, it is performed when the automatic clutch 14 is returned from the disengaged state to the fully engaged state, specifically, when the hydraulic pressure of the clutch release cylinder 34 is released. The position of the release sleeve 38 after the elapse of time is set to the learning value clamps of the clamp point clamp. The learning value clamps is equal to the actual clamp point clamp. The learning value clamps obtained by the clamp point learning unit 112 is prioritized over the clamp point clamp obtained by the clamp point correcting unit 102. That is, when the learning value clamps is obtained by the clamp point learning unit 112, the value is set as the clamp point clamp, and the clamp point clamp is corrected to an accurate value. The clamp point learning unit 112 is appropriately executed when the clamp point clamp can be learned, that is, when the automatic clutch 14 is in a fully engaged state.

  The upper / lower limit reference value setting means 114 is a correction upper limit reference value clampmax (correction upper limit threshold) and a correction lower limit reference of the clamp point clamp, which is a threshold of a range (area) that can be taken by the clamp point clamp corrected by the clamp point correction means 102. Set the value clampmin (correction lower limit threshold). The upper and lower limit reference value setting means 114 sets the correction upper limit reference value clampmax and the correction lower limit reference value clampmin with reference to the learned value clamps of the clamp point clamp obtained by the clamp point learning means 112. Since the learned clamp point clamp is in the fully engaged state of the automatic clutch 14, high reproducibility is ensured.

  Here, the upper and lower limit reference value setting means 114 is operated by the clutch temperature stability determination means 116 when the correction upper limit reference value clampmax and the correction lower limit reference value clampmin are set, specifically when the clamp point learning means 112 is executed. It is determined whether or not the clutch temperature thc of the disk 26 is in a stable state. The clutch temperature stability determination means 116 compares the clutch temperature thc of the clutch disk 26 estimated by the clutch temperature estimation means 104 with the engine water temperature Tw of the engine 12 detected by the engine cooling water temperature sensor 26, and the clutch temperature thc is It is determined whether or not the clutch temperature thc is stable based on whether or not it is near the engine coolant temperature Tw. Specifically, the clutch temperature stability determining means 116 calculates a deviation ΔT (= | thc−Tw |) between the clutch temperature thc and the engine water temperature Tw, and the deviation ΔT is less than or equal to a predetermined value α that is set in advance. In some cases, it is determined that the clutch temperature is stable. The predetermined value α is set to a value that takes into account the detection error of the engine coolant temperature sensor 56, for example.

  Here, when the clutch temperature thc is in the vicinity of the engine water temperature Tw, it is determined that the clutch temperature thc is stable because the automatic clutch 14 is accommodated in the clutch case 15 fixed to the engine 12. In a state in which heat generation and heat dissipation of the automatic clutch 14 do not occur as the vehicle 12 is adjacent to the engine 12 (for example, when fully engaged or fully released), the clutch temperature thc is equal to the heat capacity adjacent to the automatic clutch 14. This is because the temperature of the large engine 12, that is, the engine coolant temperature Tw substituted for the temperature of the engine 12 converges. Therefore, when the clutch temperature thc becomes close to the engine water temperature Tw, the clutch temperature thc of the automatic clutch 14 does not change transiently, and the clutch temperature thc becomes stable.

  When the clutch temperature stability determining unit 116 determines that the clutch temperature thc is in a stable state, the upper and lower limit reference value setting unit 114 detects the learned values clamps (clamps) obtained by the clamp point learning unit 112 at that time. Point clamp) is set to the correction lower limit reference value clampmin. Further, the upper and lower limit reference value setting means 114 adds a predetermined value β set in advance from the set correction lower limit reference value clampmin to the correction lower limit reference value clampmin, so that only the predetermined value β from the correction lower limit reference value clamp. The correction upper limit reference value clampmax (clampmin + β) set on the expansion side is calculated. The predetermined value β is experimentally obtained in advance, and is set to a constant value K obtained by experiment, for example. Alternatively, for example, the predetermined value β is obtained from the calculated clutch temperature thc based on a relationship map between the clutch temperature thc and the clamp point clamp as shown in FIG. Specifically, the predetermined value β is calculated by subtracting a clamp point clamp obtained based on the relation map from a preset specified value L. The specified value L shown in FIG. 7 is experimentally obtained in advance, and is an offset that takes into account the detection error of the clutch stroke sensor 54 and the like at the clamp point clamp at the upper limit value of the clutch temperature thc assumed when the vehicle is running, for example. It is set to the value added with the value.

  On the other hand, if it is determined by the clutch temperature stability determining means 116 that the clutch temperature thc is not in a stable state, that is, the clutch temperature thc is not near the engine water temperature Tw and the clutch temperature thc is changing transiently, the correction upper limit The reference value clampmax and the correction lower limit reference value clampmin are not set. Note that the state where the clutch temperature thc is not stable corresponds to, for example, the case where the automatic clutch 14 is in the slip state and the state immediately after the slip state.

  By the way, when the clutch temperature thc is not in a stable state, the correction value upper limit reference value and the correction value that the learning value clamps obtained by the clamp point learning unit 112 is set and entered due to errors due to variations in the clutch stroke sensor 54, etc. The lower limit reference value range (clampmin to clampmax) may be exceeded. In such a case, the upper and lower limit reference value setting means 114 resets (redefines) the learned value clamps out of the range of the correction upper limit reference value and the correction lower limit reference value to the correction upper limit reference value clampmax or the correction lower limit reference value clampmin. ) For example, when the learned value clamps is smaller than the corrected lower limit reference value clampmin, the upper / lower limit reference value setting unit 114 resets the latest learned value clamps to the corrected lower limit reference value clampmin. At this time, the correction upper limit reference value clampmax does not change. When the learned value clamps is larger than the correction upper limit reference value clampmax, the upper and lower limit reference value setting unit 114 resets the latest learned value clamps to the correction upper limit reference value clampmax. At this time, the correction lower limit reference value clampmin does not change. Further, the correction lower limit reference value clampmin and the correction upper limit reference value clampmax are set similarly when the clutch temperature is lower than a predetermined value.

  FIG. 8 shows that the controllability of the automatic clutch 14 can be improved by sequentially correcting the clamp point clamp in accordance with the main part of the control operation of the electronic control unit 44, that is, the conditions such as heat generation and heat dissipation of the automatic clutch 14. It is a flowchart for explaining a control operation, and is repeatedly executed with an extremely short cycle time of, for example, about several milliseconds to several tens of milliseconds.

  First, in step SA1 (hereinafter, step is omitted) corresponding to the clutch heat generation / radiation determination means 106 and the clutch temperature estimation means 104, the clutch temperature thc of the clutch disk 26 is calculated, and the automatic clutch 14 is activated based on the temperature change. It is determined whether or not the heat is generated. When SA1 is positive, in SA2 corresponding to the clamp point correction means 102, the clamp point clamp when the automatic clutch 14 generates heat (at the time of temperature rise) is calculated by the above-described equation (1).

  On the other hand, when SA1 is negative, whether or not the automatic clutch 14 is in the disengaged state is determined based on whether or not the clutch stroke position clts is smaller than the touch point touch in SA3 corresponding to the clutch on / off determination means 108. to decide. When SA3 is affirmed, in SA4 corresponding to the clamp point correction means 102, the clamp point clamp at the time of clutch heat dissipation (at the time of temperature decrease) and at the time of clutch disconnection is calculated by the above-described equation (2). . On the other hand, when SA3 is negative, in SA5 corresponding to the clamp point correcting means 102, the clamp point clamp at the time of clutch heat dissipation and at the time of clutch engagement is calculated by the above-described equation (3).

  In SA6 corresponding to the clamp point correction means 102, the clamp point clamp calculated in any of SA2, SA4, and SA5 is within the range of the preset correction lower limit reference value clampmin and correction upper limit reference value clampmax. It is determined whether or not there is. If SA6 is positive, the routine is terminated. On the other hand, when SA6 is negative, that is, when the calculated clamp point clamp is lower than the correction lower limit reference value clampmin, or the clamp point clamp is higher than the correction upper limit reference value clampmax, the clamp point clamp is corrected lower limit reference value clampmin or The correction upper limit reference value clampmax is corrected. Specifically, when the clamp point clamp is lower than the correction lower limit reference value clampmin, the clamp point clamp is corrected to the correction lower limit reference value clampmin, and when the clamp point clamp exceeds the correction upper limit reference value clampmax, the clamp point clamp is corrected to the upper correction limit. The reference value clampmax is corrected. Therefore, the clamp point clamp takes a range from the correction lower limit reference value clampmin to the correction upper limit reference value clampmax, and the clamp point clamp is prevented from being lower than the correction lower limit reference value clampmin or exceeding the correction upper limit reference value clampmax. .

  FIG. 9 is a flow chart for explaining a control operation for setting the correction upper limit reference value clampmax and the correction lower limit reference value clampmin of the clamp point clamp at the time of learning control of the clamp point, that is, the control point of the electronic control unit 44. is there.

  First, in step SB1 (hereinafter, step is omitted) corresponding to the clamp point learning means 112, learning control of the clamp point clamp is performed. Specifically, the position of the release sleeve 38 is measured when a predetermined time elapses while the automatic clutch 14 is switched from the disengaged state to the engaged state (connected state), and the position becomes the learning value clamps of the clamp point clamp. Is set.

  Next, at SB2 corresponding to the clutch temperature stability determining means 116, it is determined whether or not the clutch temperature thc is stable. Specifically, it is determined whether or not the clutch temperature thc is stable based on whether or not the clutch temperature thc is close to the engine water temperature Tw. When SB2 is affirmed, in SB3 corresponding to the upper and lower limit reference value setting means 114, the learned value clamps learned in SB1 is set to the corrected lower limit reference value clampmin. Further, in SB4 corresponding to the upper and lower limit reference value setting means 114, the correction upper limit reference value clampmax is calculated by adding a predetermined value β set in advance to the correction lower limit reference value clampmin set in SB3.

  On the other hand, if SB2 is negative, in SB5 corresponding to the upper and lower limit reference value setting means 114, whether or not the learned value clamps learned in SB1 has fallen below the previously set correction lower limit reference value clampmin, or correction It is determined whether or not the upper limit reference value clampmax has been exceeded. If SB5 is negative, this routine is terminated. On the other hand, when SB5 is affirmed and the learning value clamps falls below the correction lower limit reference value clampmin, the learning value clamps is a new correction lower limit in SB6 corresponding to the upper and lower limit reference value setting means 114. It is reset as the reference value clampmin. When SB5 is affirmed and the learning value clamps exceeds the correction upper limit reference value clampmax, the learning value clamps is a new correction upper limit in SB6 corresponding to the upper / lower reference value setting means 114. It is reset as the reference value clampmax.

  By setting the correction upper limit reference value clampmax and the correction lower limit reference value clampmin of the clamp point clamp as described above, as shown in FIG. 4, the clamp point clamp obtained by temperature correction is corrected with the correction lower limit reference value clampmin. It will transition between the upper limit reference value clampmax. When the correction upper limit reference value clampmax and the correction lower limit reference value clampmin are not set, the clamp point clamp may diverge as shown by the broken line when heat generation and heat dissipation are repeated in the automatic clutch 14. The reference clamp point calculation temperature threshold shown in FIG. 4 corresponds to the temperature when the clutch temperature thc approaches the engine water temperature.

  As shown in FIG. 4, when the learned value clamps falls below the correction lower limit reference value clampmin when the clutch temperature thc is not stable, the learned value clamps is reset to the correction lower limit reference value clampmin. . Similarly, although not shown in FIG. 4, when the learning value clamps exceeds the correction upper limit reference value clampmax in a state where the clutch temperature thc is not stable, the learning value clamps is restored to the correction upper limit reference value clampmax. Is set. In this way, the correction lower limit reference value clampmin or the correction upper limit reference value clampmax is reset, and the necessary minimum correction upper limit is absorbed while absorbing variations in the stroke sensor 54 and errors in the estimated clutch temperature thc. A range of the reference value and the corrected lower limit reference value is secured.

  As described above, according to the present embodiment, the correction lower limit reference value clampmin and the correction upper limit reference value clampmax are set with the clamp point clamps learned when the clutch temperature thc of the automatic clutch 14 is stable as a reference value. The In this way, with the clamp point clamps learned when the clutch temperature thc is stable as a reference value, the correction lower limit reference value clampmin and the correction upper limit reference that define the range of values that can be taken by the clamp point clamp by correction. Since the value clampmax is set, overcorrection of the clamp point clamp is prevented, and divergence of the clamp point clamp that occurs when heat generation and heat dissipation are repeated in the automatic clutch 14 can be prevented.

  Further, according to this embodiment, when the clutch temperature thc of the automatic clutch 14 is in the vicinity of the engine coolant temperature Tw of the engine coolant, it is determined that the clutch temperature thc of the automatic clutch 14 is stable. The automatic clutch 14 is adjacent to the engine 12 in a state of being accommodated in a clutch case 15 fixed to the engine 12, and is disposed in the vicinity of the engine. The clutch temperature thc converges to the temperature of the engine 12, that is, the engine water temperature Tw. Therefore, when the clutch temperature thc becomes a temperature near the engine water temperature Tw, the clutch temperature thc is stable and further contraction of the automatic clutch 14 does not occur. Therefore, such a state is defined as a state where the clutch temperature thc is stable. By setting the correction lower limit reference value clampmin and the correction upper limit reference value clampmax of the clamp point clamp, the optimum correction lower limit reference value clampmin and correction upper limit reference value clampmax can be obtained.

  According to the present embodiment, the correction lower limit reference value clampmin is the clamp point clamps learned when the clutch temperature thc of the automatic clutch 14 is stable, and the correction upper limit reference value clampmax is the correction lower limit reference value. It is calculated by adding a predetermined value β set in advance to clampmin. By doing so, it is possible to set the optimum correction lower limit reference value clampmin and the correction upper limit reference value clampmax while the clutch temperature thc of the automatic clutch 14 is stable.

  Further, according to the present embodiment, the predetermined value β is determined based on a preset constant value K or a preset relation map between the clutch temperature thc of the automatic clutch 14 and the clamp point clamp. Value. In this way, the optimum correction upper limit reference value clampmax can be set based on the determined predetermined value β.

  Further, according to the present embodiment, when the clutch temperature thc is not stable and the clamp point clamps learned at that time is lower than the correction lower limit reference value clampmin, the clamp point clamps is When the clamp point clamps is reset to the correction lower limit reference value clampmin and the clutch temperature thc is not stable and the learned clamp point clamps exceeds the correction upper limit reference value clampmax, the clamp point clamps Is reset to the correction upper limit reference value clampmax. In this way, it is possible to secure a necessary area of the clamp point clamp while absorbing variations in the clutch stroke sensor 54 and errors in the estimated value of the clutch temperature thc.

  Next, another embodiment of the present invention will be described. In the following description, parts common to the above-described embodiments are denoted by the same reference numerals and description thereof is omitted.

  FIG. 10 is a skeleton diagram illustrating a schematic configuration of a vehicle drive device 200 to which the present invention is applied. In the vehicle drive device 200 of the present embodiment, for example, the transmission 202 is disposed on the rear wheel side, and the power of the engine 204 is applied to the power transmission shaft 207 and the automatic clutch 208 (the friction clutch of the present invention) covered with the torque tube 206. ) Is transmitted to the transmission 202. Note that the basic structures of the transmission 202 and the automatic clutch 208 are substantially the same as those of the transmission 16 and the automatic clutch 14 of the above-described embodiment, and thus description thereof is omitted.

  In this embodiment, as shown in FIG. 10, the automatic clutch 208 is disposed adjacent to the transmission 202, while the engine 204 and the automatic clutch 208 have a power transmission shaft 207 covered with a torque tube 206. It is arranged at a position away via.

  In the vehicle drive device 200 configured as described above, when there is no heat generation or heat dissipation in the automatic clutch 208, the clutch temperature thc of the automatic clutch 208 is the temperature of the transmission 202 adjacent to the automatic clutch 208, that is, the transmission. It will converge to 202 hydraulic oil temperature Toil. Therefore, in this embodiment, when the clutch temperature thc of the automatic clutch 202 becomes the hydraulic oil temperature Toil, it is determined that the clutch temperature thc is stable.

  In the electronic control unit 212 of the present embodiment, the clutch temperature stability determining means 214 indicates that the clutch temperature thc of the automatic clutch 208 is stable when the clutch temperature thc is in the vicinity of the hydraulic oil temperature Toil of the automatic transmission 202. to decide. Specifically, the clutch temperature stability determining means 214 detects the hydraulic oil temperature Toil of the transmission 202 by the hydraulic oil temperature sensor 210, and a deviation between the detected hydraulic oil temperature Toil and the clutch temperature thc is preset. When it is below the predetermined value, it is determined that the clutch temperature thc is stable. As described above, when the automatic clutch 208 is disposed adjacent to the transmission 202, it is determined whether or not the clutch temperature thc is stabilized based on the hydraulic oil temperature Toil of the transmission 202. The other main control operations of the electronic control unit 212 are substantially the same as those of the electronic control unit 44 of the above-described embodiment, and thus the description thereof is omitted.

  As described above, according to the present embodiment, the automatic clutch 208 is disposed adjacent to the transmission 202, and the clutch temperature thc of the automatic clutch 208 is in the vicinity of the hydraulic oil temperature Toil of the transmission 202. At this time, it is determined that the clutch temperature thc of the automatic clutch 208 is stable. When the automatic clutch 208 is disposed adjacent to the transmission 202, the clutch temperature thc converges to the hydraulic oil temperature Toil of the transmission 202 when there is no heat generation or heat dissipation in the automatic clutch 208. Accordingly, when the clutch temperature thc becomes a temperature near the hydraulic oil temperature Toil of the transmission 202, the clutch temperature thc is stable and further contraction of the automatic clutch does not substantially occur. Therefore, the clutch temperature thc is stabilized in this state. By setting the correction lower limit reference value clampmin and the correction upper limit reference value clampmax of the clamp point clamp as the state, it is possible to obtain the optimum correction lower limit reference value clampmin and the correction upper limit reference value clampmax, which is the same as the above-described embodiment. An effect can be obtained.

  As mentioned above, although the Example of this invention was described in detail based on drawing, this invention is applied also in another aspect.

  For example, in the above-described embodiment, the automatic clutch 14 is used. However, the present invention is not necessarily limited to the automatic clutch 14. For example, the synchronous clutch type parallel twin-shaft transmission is provided with two systems of input shafts. There is no contradiction if it is a friction clutch, such as a so-called DCT (Dual Clutch Transmission) friction clutch, which is a transmission of a type in which a friction clutch is connected to the input shaft of each system and further connected to even and odd stages. Can be used freely in range.

  Further, in the above-described embodiment, the clutch temperature thc of the automatic clutch 14 is calculated, but it may be detected directly by a temperature sensor.

  In the above-described embodiment, the clutch stroke position clts is defined as the movement position of the release sleeve 38. However, the movement position of the piston 40 of the clutch release cylinder 34 may be defined as the clutch stroke position clts.

  In the above-described embodiment, the clutch release cylinder 34 is configured by a hydraulic actuator. However, the clutch release cylinder 34 is not necessarily limited to a hydraulic actuator, and may be configured by, for example, an electric actuator.

  In the above-described embodiment, the automatic clutch 14 is a dry single-plate friction clutch, but the present invention is not limited to a dry clutch, and can be applied to a wet clutch.

  The above description is only an embodiment, and the present invention can be implemented in variously modified and improved forms based on the knowledge of those skilled in the art.

12, 204: Engine 14, 208: Automatic clutch (friction clutch for vehicle)
16, 202: Transmission 20: Crankshaft (crankshaft)
34: Clutch release cylinder (actuator)
44, 212: Electronic control unit
clamp: Clamp point
clampmin: Correction lower limit reference value
clampmax: Correction upper limit reference value K: Fixed value
thc: Clutch temperature Tw: Engine water temperature Toil: Hydraulic oil temperature β: Predetermined value

Claims (6)

In a vehicle friction clutch controlled by an actuator, a vehicle that corrects a clamp point at which the friction clutch is completely engaged based on the temperature of the friction clutch, and controls the friction clutch based on the corrected clamp point A friction clutch control device,
Using the clamp point learned when the clutch temperature of the friction clutch is stable as a reference value, a correction lower limit reference value and a correction upper limit reference value that define a range of values that the clamp point can take are set by the correction. A friction clutch control device for a vehicle. The friction clutch is adjacent to the engine in a state of being housed in a clutch case fixed to the engine, and is a dry clutch for selectively interrupting a power transmission path between a crankshaft of the engine and a transmission. And
2. The control apparatus for a friction clutch for a vehicle according to claim 1, wherein the clutch temperature of the friction clutch is determined to be stable when the clutch temperature of the friction clutch is close to the engine coolant temperature of engine cooling water. The friction clutch is disposed adjacent to the transmission;
2. The friction clutch control device for a vehicle according to claim 1, wherein the clutch temperature of the friction clutch is determined to be stable when the clutch temperature of the friction clutch is near the hydraulic oil temperature of the transmission. . The correction lower limit reference value is the clamp point learned when the clutch temperature of the friction clutch is stable,
4. The vehicle friction clutch control device according to claim 1, wherein the correction upper limit reference value is calculated by adding a predetermined value set in advance to the correction lower limit reference value. .   5. The predetermined value is a predetermined value set in advance or a value determined based on a preset relationship map between a clutch temperature of the friction clutch and a clamp point. Control device for vehicle friction clutch. When the clutch temperature is not stable, and the clamp point learned at that time is lower than the correction lower limit reference value, the clamp point is reset to the correction lower limit reference value,
When the clutch temperature is not stable and the clamp point learned at that time exceeds the correction upper limit reference value, the clamp point is reset to the correction upper limit reference value. The control apparatus for a friction clutch for a vehicle according to any one of claims 1 to 5.

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