JP2006194392A - Transmission control device with input torque control of disk/roller type continuously variable transmission - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve a transmission control device to prevent the speed of a disk/roller type continuously variable transmission from being changed to the maximum transmission gear ratio or the minimum transmission gear ratio even when an oil flow control valve for transmission control of the transmission sticks to the open state where oil pressure is continuously supplied. <P>SOLUTION: When the oil flow control valve for transmission control of the disk/roller type continuously variable transmission sticks to the open state where oil pressure is continuously supplied, transmission control is performed by control of drive torque of a power source driving the continuously variable transmission. When oil flow control valves are divided into an oil flow control valve for increasing speed and that for reducing speed, the oil flow control valve which does not stick to the open state may be oppositely opened. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a shift control device for a disk / roller type continuously variable transmission.

  A disk / roller type continuously variable transmission is known as a continuously variable transmission that drives a load with a power source. The disc / roller type continuously variable transmission increases the gear ratio when the trunnion carrying the roller is biased in the rotational direction of the drive side disc from the neutral position where the central axis of the roller intersects the central axis of the disc. If it is biased in the opposite direction, the gear ratio is reduced. In such a disk / roller type continuously variable transmission, the trunnion has a first pressure receiving surface for biasing it to the gear ratio decreasing side (speed increasing side) and it to the gear ratio increasing side (deceleration side). A hydraulic cylinder coupled to a piston having a second pressure receiving surface for biasing and forming first and second hydraulic chambers for the first and second pressure receiving surfaces of the piston; and the first and second The hydraulic flow control valve for controlling the supply and discharge of the hydraulic pressure to and from the hydraulic chamber and the shift control means for controlling the operation of the oil flow control valve are operated together with a hydraulic shift control device. Since the roller engagement surface of the disk of the disk / roller type continuously variable transmission is usually a part of the toroidal surface, the disk / roller type continuously variable transmission is also called a toroidal type continuously variable transmission. Yes.

A hydraulic shift control device for controlling the shift of a disc / roller type continuously variable transmission is provided between first and second ports that communicate oil supply from a pressure oil source to first and second hydraulic chambers. A hydraulic circuit device having a servo valve for switching and correspondingly switching the connection of the second and first ports to the oil drainage path is provided. The servo valve in such a hydraulic transmission control device is generally a spool valve that switches between opening and closing of an oil supply port and an oil discharge port in accordance with the switching movement of the valve spool. An example of a hydraulic circuit device including a so-called 4-port type servo valve having two hydraulic supply ports and two drain ports as a spool valve is shown in Patent Document 1 below.
JP-A-10-274301

  In a hydraulic servo valve, particularly a spool valve, when a foreign object is caught between the spool and the cylinder, the smooth movement of the spool for opening and closing the valve is hindered, and a state where the spool is fixed to the cylinder (stick) is generated. There is a fear. If a stick is generated in the oil flow control valve of the shift control device of the disk / roller type continuously variable transmission, the transmission may be shifted to the maximum gear ratio or the minimum gear ratio. In particular, in a disc / roller type continuously variable transmission, a biasing force acting on the trunnion toward the gear ratio increasing side acts on the trunnion due to the drive torque acting on the roller from the disc, so that the transmission is easily decelerated to the maximum gear ratio.

  The present invention addresses the above-described problems in a disk / roller type continuously variable transmission, and is a shift control capable of controlling the shift of a disk / roller type continuously variable transmission without using a hydraulic servo device using a servo valve. An object is to provide an apparatus.

  In order to solve the above-described problems, the present invention provides a shift control device for a disk / roller type continuously variable transmission that drives a load by a power source, and uses a displacement for changing the speed ratio of the continuously variable transmission. The present invention proposes a speed change control device having a displacement control means for controlling by controlling the torque of the load.

  In this case, the speed change control device has another displacement control means for controlling the displacement for changing the speed ratio of the continuously variable transmission, and the displacement control means for controlling the torque value of the load is the other speed control means. One of the displacement control means may be activated when a failure that prevents its normal operation occurs. The other one displacement control means may be a hydraulic servo device.

  The hydraulic servo apparatus includes a piston having a first pressure receiving surface for displacing the continuously variable transmission to the speed increasing side and a second pressure receiving surface for displacing the continuously variable transmission to the deceleration side; A hydraulic cylinder forming first and second hydraulic pressure chambers for the first and second pressure receiving surfaces of the piston, and an electromagnetically operated oil flow for supplying and discharging hydraulic pressure to and from the first and second piston pressure receiving surfaces A control valve and a speed change control means for controlling the operation of the oil flow control valve, and the oil flow control valve has the second piston with respect to the first piston pressure receiving surface when energization thereto is cut off. A higher hydraulic pressure with respect to the pressure receiving surface may be maintained. In this case, the oil flow control valve includes a first oil flow control valve that supplies and discharges hydraulic pressure to and from the first piston pressure receiving surface and a second oil that supplies and discharges hydraulic pressure to and from the second piston pressure receiving surface. And when the first and second oil flow control valves are de-energized, the hydraulic pressure that the first oil flow control valve holds against the first piston pressure receiving surface is The second oil flow control valve may be higher than the hydraulic pressure held with respect to the second piston pressure receiving surface.

  The hydraulic servo apparatus includes a piston having a first pressure receiving surface for displacing the continuously variable transmission to the speed increasing side and a second pressure receiving surface for displacing the continuously variable transmission to the deceleration side. A hydraulic cylinder that forms first and second hydraulic chambers for the first and second pressure receiving surfaces of the piston, and an oil flow control that supplies and discharges hydraulic pressure to and from the first and second piston pressure receiving surfaces And a shift control means for controlling the operation of the oil flow control valve, and when the oil flow control valve is fixed in a state of continuously supplying hydraulic pressure to the second piston pressure receiving surface, The output torque of the power source may be reduced in response to an increase in hydraulic pressure with respect to the second piston pressure receiving surface. In this case, the hydraulic servo device includes a first oil flow control valve that supplies and discharges hydraulic pressure to and from the first piston pressure receiving surface, and a second oil flow control that supplies and discharges hydraulic pressure to and from the second piston pressure receiving surface. And when the second oil flow control valve is fixed in a state where it continues to supply hydraulic pressure to the second piston pressure receiving surface, the second oil flow control valve causes the first piston pressure receiving surface to It is possible to increase the supply hydraulic pressure to the.

  The hydraulic servo device includes a piston having a first pressure receiving surface for displacing the continuously variable transmission to the speed increasing side and a second pressure receiving surface for displacing the continuously variable transmission to the deceleration side; A hydraulic cylinder that forms first and second hydraulic pressure chambers for the first and second pressure receiving surfaces of the piston, and an oil flow control valve that supplies and discharges hydraulic pressure to and from the first and second piston pressure receiving surfaces Shift control means for controlling the operation of the oil flow control valve, and when the oil flow control valve is fixed in a state of continuously supplying hydraulic pressure to the first piston pressure receiving surface, The output torque of the power source may be increased in response to an increase in the hydraulic pressure with respect to the first piston pressure receiving surface. Also in this case, the hydraulic servo device includes a first oil flow control valve that supplies and discharges hydraulic pressure to and from the first piston pressure receiving surface and a second oil that supplies and discharges hydraulic pressure to and from the second piston pressure receiving surface. A flow control valve, and when the first oil flow control valve is fixed in a state of continuously supplying hydraulic pressure to the first piston pressure receiving surface, the second oil flow control valve causes the second piston to The supply hydraulic pressure with respect to the pressure receiving surface may be increased.

  A shift control device for a disk / roller type continuously variable transmission that drives a load by a power source has a displacement control means for controlling the displacement for changing the transmission ratio of the continuously variable transmission by controlling the torque of the load. If so, the continuously variable transmission can be controlled by controlling the torque that the disk / roller type continuously variable transmission transmits to the load from the power source without depending on the shift control device using the hydraulic servo valve. It is possible to control the displacement required for the gear ratio control of the gear and to control the gear ratio of the continuously variable transmission.

  In a drive system in which a load is driven from a power source via a disk / roller type continuously variable transmission, auxiliary automatic control is usually performed by auxiliary control means equipped with a computer, so load torque is controlled for shift control. However, since the change in the speed ratio required for the continuously variable transmission is not necessarily uniquely related to the value of the load torque of the drive system, other than the displacement control means based on the load torque. In addition, if the speed change control device has another displacement control means, the continuously variable transmission can obtain a degree of freedom in terms of operating performance such that the speed ratio can be controlled without being constrained by the load torque. If the other displacement control means is a hydraulic servo device, the continuously variable transmission can obtain a high speed ratio control performance.

  When the other one displacement control means is a hydraulic servo device, the hydraulic servo device moves the first pressure receiving surface and the continuously variable transmission for displacing the continuously variable transmission to the acceleration side to the deceleration side. A piston having a second pressure receiving surface for displacement; a hydraulic cylinder forming first and second hydraulic chambers for the first and second pressure receiving surfaces of the piston; and the first and second An electromagnetically operated oil flow control valve that supplies and discharges hydraulic pressure to and from the piston pressure receiving surface; and a shift control means that controls the operation of the oil flow control valve, and the oil flow control valve is cut off from energization thereto. When the hydraulic pressure is higher than that of the second piston pressure receiving surface with respect to the first piston pressure receiving surface, an electromagnetically operated oil flow control can be performed when there is any obstacle to the operation of the hydraulic servo device. By shutting off the energization of the valve Since the hydraulic pressure for the first piston pressure receiving surface is higher than the hydraulic pressure for the second piston pressure receiving surface, the force acting on the piston and the force acting on the piston due to load torque are opposed to each other due to the hydraulic pressure difference. By increasing or decreasing the force acting on the piston by the load torque relative to the force acting on the piston due to the hydraulic pressure difference, the gear ratio can be controlled in either direction. In this case, the oil flow control valve supplies and discharges hydraulic pressure to and from the first piston pressure receiving surface, and the second oil flow control supplies and discharges hydraulic pressure to and from the second piston pressure receiving surface. And the first and second oil flow control valves are hydraulic pressures that the first oil flow control valve holds against the first piston pressure-receiving surface when the power supply to the first and second oil flow control valves is cut off. Is achieved by setting the clearance leakage of the first and second oil flow control valves so that the second oil flow control valve is higher than the hydraulic pressure held by the second piston pressure receiving surface. Can do.

  A hydraulic servo device includes a piston having a first pressure receiving surface for displacing the continuously variable transmission to the speed increasing side and a second pressure receiving surface for displacing the continuously variable transmission to the deceleration side; A hydraulic cylinder forming first and second hydraulic pressure chambers for the first and second pressure receiving surfaces, an oil flow control valve for supplying and discharging hydraulic pressure to the first and second piston pressure receiving surfaces, and the oil Shift control means for controlling the operation of the flow control valve, and when the oil flow control valve is fixed in a state of continuously supplying hydraulic pressure to the second piston pressure-receiving surface, the second piston due to the fixation If the output torque of the power source is reduced in response to an increase in the hydraulic pressure with respect to the pressure receiving surface, the oil flow control valve is fixed in a state where the oil pressure continues to be supplied to the second piston pressure receiving surface. Reduce the output torque of the power source. It said piston to thereby alleviate the tendency of change gear ratio of the speed reduction direction acting, it is possible to suppress the increase of excessive speed ratio by. In this case, a first oil flow control valve that supplies and discharges hydraulic pressure to and from the first piston pressure receiving surface and a second oil flow control valve that supplies and discharges hydraulic pressure to and from the second piston pressure receiving surface. And the second oil flow control valve is fixed to the second piston pressure receiving surface in a state of continuously supplying hydraulic pressure to the first piston pressure receiving surface. If the supply hydraulic pressure is increased, the shift control by reducing the output torque of the power source can be more accurately executed.

  Further, the hydraulic servo apparatus has a piston having a first pressure receiving surface for displacing the continuously variable transmission to the acceleration side and a second pressure receiving surface for displacing the continuously variable transmission to the deceleration side, and A hydraulic cylinder that forms first and second hydraulic chambers for the first and second pressure receiving surfaces of the piston; an oil flow control valve that supplies and discharges hydraulic pressure to and from the first and second piston pressure receiving surfaces; Shift control means for controlling the operation of the oil flow control valve, and when the oil flow control valve is fixed in a state of continuously supplying hydraulic pressure to the first piston pressure receiving surface, the first due to the fixation If the output torque of the power source is increased in response to an increase in the hydraulic pressure with respect to the piston pressure receiving surface, the oil flow control valve continues to supply the hydraulic pressure to the first piston pressure receiving surface. When fixed, the piston is hydraulically The output torque of the power source is made to oppose the changing tendency of the transmission gear ratio in the speed increasing direction to suppress the excessive reduction of the gear ratio, and the gear ratio is controlled in both the deceleration direction and the speed increasing direction. be able to. In this case as well, a first oil flow control valve that supplies and discharges hydraulic pressure to and from the first piston pressure receiving surface and a second oil flow that supplies and discharges hydraulic pressure to and from the second piston pressure receiving surface. And when the first oil flow control valve is fixed in a state of continuously supplying hydraulic pressure to the first piston pressure receiving surface, the second oil pressure control valve causes the second piston pressure receiving pressure to If the hydraulic pressure supplied to the surface is increased, the shift control by increasing the output torque of the power source can be executed more accurately.

  FIG. 1 attached herewith is a schematic diagram showing one embodiment of a shift control apparatus for a disk / roller type continuously variable transmission according to the present invention. In the figure, reference numeral 10 denotes a power roller having a well-known structure as a toroidal-type continuously variable transmission, which is supported by a trunnion 12 via an eccentric shaft 14, and a part of the drive side disk is shown as a virtual line as Dd. Rotation transmitted between the pair of disks by changing the tilt angle with respect to the pair of disks, arranged in a state of being pressed between the pair of disks on the driving side and the driven side as shown in FIG. The gear ratio of the load power is changed. In the illustrated example, the drive side disk Dd is counterclockwise in the figure by a power source E such as an internal combustion engine (engine) shown behind the power roller 10 as seen in FIG. It is driven in the turning direction, and a downward force Fs is exerted on the power roller 10 by a driving torque during driving. The change of the tilt angle of the power roller with respect to the pair of disks is brought about by the trunnion 12 being temporarily displaced up and down in the drawing by the hydraulic actuator 16.

  That is, when the center axis Cr of the power roller intersects the center axis Cd of the disk, the power disk is at the contact point Pc with the power roller regardless of the tilt angle of the power roller with respect to the disk. The force exerted on the roller (and the force exerted by the driven disk on the power roller as a reaction to it) acts in parallel to the tilt axis of the power roller, so no force that changes the tilt angle acts on the power roller. When the center axis of the roller is displaced either up or down with respect to the center axis of the disk, the power roller is as long as the direction of displacement is along the direction of rotation of the disk as viewed at the contact point between the power roller and the drive side disk. Since a force in the direction of moving it toward the center of the driving disk acts on the power roller, the power roller increases the speed ratio (immediately If the displacement direction is a direction opposite to the rotation direction of the driving disk, a force in a direction away from the center of the driving disk acts on the power roller. The power roller is tilted in a direction that reduces the gear ratio (that is, the upshift direction).

  Thus, when the gear ratio should be kept constant, the trunnion is applied with a force that resists the driving force exerted on the power roller from the driving side disk so that the central axis of the power roller is the driving side disk (and therefore also the driven side disk). ) At a position that intersects the central axis of the disk, and the speed ratio should be changed, the speed ratio can be increased or decreased by temporarily displacing the center axis of the power roller with respect to the center axis of the disk at any time. In general, two power rollers are arranged symmetrically between a pair of disks or three are arranged in a three-piece configuration, and when two sets are arranged symmetrically, the other of the power roller 10 shown in the figure is paired with the other. The power roller is displaced upward from the neutral position when the gear ratio is changed to the increasing side, and is displaced downward from the neutral position when the gear ratio is changed to the decreasing side.

  The hydraulic actuator 16 includes a piston 18 connected to the lower end of the trunnion 12, and a cylinder 24 that forms a hydraulic chamber 20 below the piston and forms a hydraulic chamber 22 above the piston. As the oil is supplied into the hydraulic chamber 20 and the oil in the hydraulic chamber 22 is discharged from the port 28, the piston 18 is displaced upward to cause an upshift, and conversely from the port 28 into the hydraulic chamber 22. When oil is supplied and oil in the hydraulic chamber 20 is discharged from the port 26, the piston 18 is displaced downward to cause a downshift. The piston has a shaft portion 30 that penetrates the lower hydraulic chamber 20 and the upper hydraulic chamber 22, and the piston 18 has a lower piston pressure receiving surface 32 that displaces the trunnion 12 toward the acceleration side and the trunnion 12 on the deceleration side. An upper pressure-receiving surface 34 that is biased toward the upper side is formed.

  A hydraulic pump 36 serves as a supply source of pressure oil to the hydraulic chambers 20 and 22, and a waste oil reservoir 38 receives oil discharged from the hydraulic chambers 20 and 22. Supply of pressure oil from the hydraulic pump 36 to the hydraulic chambers 20, 22 and discharge of oil from the hydraulic chambers 20, 22 to the drain oil reservoir 38 are controlled by individual oil flow control valves 40 and 42. Yes.

  The oil flow control valve 40 includes an oil supply port 44 that receives supply of pressure oil from the hydraulic pump 36, an oil discharge port 46 that discharges oil toward the oil discharge reservoir 38, and an inlet / outlet port 48 that is connected to the hydraulic chamber 20. A valve housing 50, a valve spool 52 that controls communication and blocking between the ports 44, 46, and 48, a compression coil spring 54 that biases the valve spool 52 leftward in the drawing, And an electromagnetic drive device 56 that drives the valve spool 52 to the right in the drawing against the spring force. The inlet / outlet port 48 communicates only with the oil supply port 44, communicates only with the oil discharge port 46, or is cut off from both the oil supply port 44 and the oil discharge port 46 depending on the movement position of the valve spool 52. Is done. That is, when the valve spool 52 is in the switching position shown in the lower half of the figure, the inlet / outlet port 48 is communicated with the oil supply port 44 and shut off from the oil discharge port 46, and the valve spool 52 is shown in the upper half of the figure. When the valve spool 52 is in the intermediate position, the inlet / outlet port 48 is disconnected from the oil supply port 44 and communicated with the oil discharge port 46. It is cut off from any of the oil discharge ports 46.

  Similarly, the oil flow control valve 42 includes an oil supply port 58 that receives supply of pressure oil from the hydraulic pump 36, an oil discharge port 60 that discharges oil toward the oil discharge reservoir 38, and an inlet / outlet port 62 connected to the hydraulic chamber 22. , A valve spool 66 for controlling communication and blocking between the ports 58, 60, 62, a compression coil spring 68 for urging the valve spool 66 leftward in the figure, and a compression coil An electromagnetic drive device 70 that drives the valve spool 66 to the right in the drawing against the spring force of the spring 68 is provided. Depending on the movement position of the valve spool 66, the inlet / outlet port 62 is connected only to the oil supply port 58, is connected only to the oil discharge port 60, or is cut off from both the oil supply port 58 and the oil discharge port 60. Is done. That is, when the valve spool 66 is in the switching position shown in the upper half of the figure, the inlet / outlet port 62 is communicated with the oil supply port 58 and cut off from the oil discharge port 60, and the valve spool 66 is in the lower half of the figure. When the valve spool 66 is in the intermediate position, the inlet / outlet port 62 is disconnected from the oil supply port 58 and communicated with the oil discharge port 60. It is cut off more than any of the oil discharge ports 60.

  Energization of the electromagnetic drive devices 56 and 70 is controlled by a shift control means 72 having a microcomputer. The shift control means 72 can also control the output torque of a power source (engine in the illustrated example) E that drives the drive side disk Dd.

  In the structure as described above, control of the gear ratio of the disk / roller type continuously variable transmission by switching control of the oil flow control valves 40 and 42 is performed as follows. First, when the gear ratio should be reduced, the shift control means 72 controls the supply of current to the electromagnetic drive devices 56 and 70 of the oil flow control valves 40 and 42, and temporarily opens and closes the access port 48 of the oil flow control valve 40. At the same time, the oil is supplied to the hydraulic chamber 20 by communicating with the oil supply port 44, and at the same time, the inlet / outlet port 62 of the oil flow control valve 42 is temporarily connected to the oil discharge port 60 to discharge the oil from the hydraulic chamber 22, 18 is driven upward in the figure, and the center axis Cr of the roller 10 is biased upward with respect to the center axis Cd of the disk. When the central axis of the roller 10 is biased upward with respect to the central axis of the disk, the roller is deflected in a direction that reduces the transmission ratio, so that the resulting change in the transmission ratio is not shown in the figure. This signal is detected by a sensor or the like that detects the deflection angle of the roller, and the signal is sent to the speed change control means 72. The speed change control means 72 executes appropriate feedback control as the speed change ratio changes, and a desired tilt occurs in the roller 10. Alternatively, when the prospect of occurrence is established, the supply current to the electromagnetic driving devices 56 and 70 is controlled to return the piston 18 to the neutral position.

  Conversely, when the gear ratio of the disc / roller type continuously variable transmission should be increased, the shift control means 72 controls the supply of current to the electromagnetic drive devices 56 and 70 of the oil flow control valves 40 and 42 to The inlet / outlet port 48 of the flow control valve 40 is temporarily connected to the oil discharge port 46 to discharge oil from the hydraulic chamber 20, and at the same time, the inlet / outlet port 62 of the oil flow control valve 42 is temporarily connected to the oil supply port 58. Then, the oil is fed into the hydraulic chamber 22 and the piston 18 is driven downward in the figure to bias the central axis Cr of the roller 10 downward with respect to the central axis Cd of the disk. Also in this case, if the central axis of the roller 10 is biased downward with respect to the central axis of the disk, the roller is deflected in a direction that increases the transmission ratio, and the resulting change in the transmission ratio is shown in the figure. This is detected by a sensor or the like that detects the deflection angle of the roller not shown, and the signal is sent to the speed change control means 72. The speed change control means 72 executes appropriate feedback control as the speed change ratio changes, and the roller 10 receives the desired value. When the tilting or the prospect of the occurrence of the tilting occurs, the current supplied to the electromagnetic driving devices 56 and 70 is controlled to return the piston 18 to the neutral position.

  The vertical deviation of the power roller with respect to the disk for changing the gear ratio of the disk / roller type continuously variable transmission as described above is also performed by changing the output torque of the power source E by the shift control means 72. That is, in the illustrated example, the drive side disk Dd is behind the power roller 10 as shown in FIG. 1 and is driven counterclockwise by the power source E as shown in FIG. Since a downward force Fs is applied to the roller 10 in the figure, increasing the driving load torque causes the power roller 10 to be biased downward with respect to the disk, and conversely reduces the driving load torque. By doing so, the power roller 10 can be biased upward with respect to the disk.

  When the load is driven from the power source via the disk / roller type continuously variable transmission is a drive system in the vehicle, such a vehicle is naturally provided with a driving assistance control means by a computer, and the driver The driving assist control means corrects the output torque of the power source commanded by the vehicle according to the operation status of the vehicle, and the operation of the driving assist control means includes a shift control. There is no problem in controlling the load torque. However, when the shift control means based on load torque control is provided in combination with the hydraulic shift control means based on the oil flow control valve as shown in FIG. It may be operated as an emergency alternative control means when a failure that hinders the normal operation such as opening / closing failure due to biting or the like occurs.

  FIG. 2 is a flowchart showing a procedure for operating the shift control means by load torque control in such a manner. In this case, when the control is started, it is monitored whether or not the hydraulic control device is operating normally in step 100 (S100) of the flow cycle with a period of several milliseconds to several hundred milliseconds, and the answer is yes. If (Y), the control proceeds to step 200, and the shift control by the oil flow control valves 40 and 42 described above is performed. When the answer is no (N)-, the control proceeds to step 300 and the shift is performed. The control means 72 controls the output torque of the power source E to change the speed.

  In this case, as shown in FIG. 1, in the structure in which the shift control means by hydraulic pressure and the shift control means by load torque control are combined, when the shift control by load torque control is performed, as an example, the oil flow control valve 40 and 42, and by appropriately designing the clearance between the valve housings 50, 64 and the valve spools 52, 66 at the respective port portions of the oil flow control valves 40 and 42, When the energization of the flow control valves 40 and 42 is interrupted, a certain hydraulic pressure is maintained on the piston pressure receiving surface 32 by the closed oil flow control valve 40, and the closed oil flow control valve 42 is also closed. Thus, a certain oil pressure is held on the piston pressure receiving surface 34, and the oil pressure held on the piston pressure receiving surface 32 is a predetermined differential pressure from the oil pressure held on the piston pressure receiving surface 34. If the pressure is increased, the gear ratio is changed to the speed reduction side or the speed increase side by increasing or decreasing the force due to the load torque acting downward with respect to the upward force acting on the piston 18 due to the differential pressure. be able to.

  FIG. 3 is a flowchart showing an example of a procedure for controlling the transmission ratio of the disk / roller type continuously variable transmission by the transmission control apparatus of the present invention. The control according to this flowchart is also performed while reading necessary information from various sensors or the like at a cycle of several milliseconds to several hundred milliseconds.

  When the control is started, solid foreign matter is caught in the oil flow control valve 40 in FIG. 1 which changes the transmission ratio of the continuously variable transmission to the reduction side in step 1 based on the read information. It is determined whether or not sticking (stick) in the open state has occurred. If the answer is no, the control proceeds to step 2, and the oil flow control valve 42 in FIG. It is determined whether or not (stick) has occurred. If the answer is no, the control proceeds to step 3 and shift control according to the shift request is performed in the following manner.

  In step 3, it is now assumed that the power source is an engine (internal combustion engine). Based on the accelerator opening θ and the vehicle speed V, a predetermined map or the like is referred to, and a function γt = f of θ and V is obtained. The target gear ratio γt is calculated as (θ, V). Next, in step 4, a deviation Δγ between the target speed ratio γt calculated above and the current speed ratio γ is calculated.

  Next, in step 5, it is determined whether or not Δγ is greater than or equal to a certain positive minute value δa. If the answer is yes, control proceeds to step 6, and in the example of FIG. 1, the oil supply port 58 of the oil flow control valve 42 is opened with respect to the inlet / outlet port 62, and the hydraulic pressure Pd in the hydraulic chamber 22 of the hydraulic actuator 16 is set to 1. The flow rate is increased by k1Δγ per flow cycle, and at the same time, the oil discharge port 46 of the oil flow control valve 40 is opened with respect to the access port 48, and the hydraulic pressure Pu in the hydraulic chamber 20 of the hydraulic actuator 16 is decreased by k1Δγ per flow cycle. 18 is displaced downward in the figure. k1 is an appropriate proportionality constant.

  On the other hand, if the answer to step 5 is no, the control proceeds to step 7, and it is determined whether or not Δγ is equal to or smaller than a certain negative minute value −δa. If the answer is yes, control proceeds to step 8 where the oil supply port 44 of the oil flow control valve 40 is opened with respect to the inlet / outlet port 48 and the hydraulic pressure Pu in the hydraulic chamber 20 of the hydraulic actuator 16 is increased by k1Δγ per flow cycle. At the same time, the oil discharge port 60 of the oil flow control valve 42 is opened with respect to the inlet / outlet port 62 to reduce the hydraulic pressure Pd in the hydraulic chamber 22 of the hydraulic actuator 16 by k1Δγ per flow cycle, and the piston 18 is moved upward in the figure. Biasing is performed.

  If the answer to step 7 is no, the control is returned as it is, the opening / closing control of the oil flow control valves 40 and 42 is not performed, and the piston 18 in the hydraulic actuator 16 is held in the same position.

  When the oil flow control valve 42 is stuck (stick) in the open state due to the biting of solid foreign matters, and the answer to step 2 is yes, the control proceeds to step 9 and the hydraulic pressure in the hydraulic chamber 20 of the hydraulic actuator 16 is increased. Increasing Pu to some predetermined value Puc is performed. Thereafter, the control proceeds to step 10, and based on the throttle opening θ and the vehicle speed V, the function γt = f (θ, V) of θ and V is referred to in the same manner as in step 3 with reference to a preset map or the like. ), The target gear ratio γt is calculated. Next, in step 11, a deviation Δγ between the target speed ratio γt calculated above and the current speed ratio γ is calculated.

  Next, at step 12, it is determined whether or not Δγ is greater than or equal to a positive minute value δa. In this case, the upper pressure receiving surface 32 of the piston 18 is continuously supplied with the pressure oil Pds1 (FIG. 4) from the oil supply port 58 of the oil flow control valve 42 fixed in the open state. If a downward force is acting in the figure based on the drive torque transmitted from the roller to the roller 10, but the target gear ratio γt is still higher than the current gear ratio γ and the answer to step 12 is yes, the control is Proceeding to step 13, the engine output torque Te is increased by k2Δγ per one flow cycle separately from the setting of the throttle opening θ corresponding to the driver's accelerator pedal depression. Increasing the input torque to the continuously variable transmission causes the piston 18 to be biased downward in the figure. k2 is an appropriate constant.

  On the other hand, the oil flow control valve 42 is fixed in the open state, pressure oil is continuously supplied from the oil supply port 58 to the inlet / outlet port, and the piston 18 is directed downward in the figure by the driving torque transmitted from the disk to the roller 10. In the state where the force is acting, the answer of step 12 will eventually become no, and the answer of step 14 will become yes. At this time, the control proceeds to step 15 where the engine output torque Te is reduced by k2Δγ per flow cycle separately from the setting of the throttle opening θ corresponding to the driver's depression of the accelerator pedal. If the engine output torque Te is reduced, the downward force applied to the trunnion is correspondingly reduced, stopping the displacement of the piston 18 in the downshift direction and possibly pushing the piston 18 back in the upshift direction. It is also possible.

  FIG. 4 shows that when the answer to step 2 is changed from no to yes at time t1, the control in steps 9 to 15 is performed, and an excessive increase in the gear ratio is suppressed by controlling the output torque of the engine. It is a graph which shows the state to be. The speed ratio temporarily increases from time t1 due to the increase in downshift side hydraulic pressure Pd from time t1, but returns to the target speed ratio γt at time t2 due to increase in upshift side hydraulic pressure to Puc and reduction in engine torque Te. When the increase in the downshift side hydraulic pressure Pd due to the open stick generated in the oil flow control valve 42 is relatively low, such as Pds2 indicated by the broken line in FIG. 4, the upshift side hydraulic pressure Pu is indicated by the broken line in FIG. As shown in (3), it may be left as it is without being particularly increased. This is that step 9 is substantially omitted.

  Further, when the oil flow control valve 40 is stuck in an open state due to the biting of solid foreign matters, and the answer to step 1 becomes yes, the control proceeds to step 16, and the control in the hydraulic chamber 22 of the hydraulic actuator 16 is performed. The hydraulic pressure Pd is increased to a certain predetermined value Pdc1 (FIG. 4). Thereafter, the control proceeds to step 10, and steps 10 to 15 are similarly performed in the manner described above.

  FIG. 5 shows that when the answer to step 1 turns from yes to yes at time t1, the control in steps 16 and 10 to 15 is performed, and the gear ratio is excessively reduced by controlling the output torque of the engine. It is a graph which shows the state where is suppressed. The transmission gear ratio temporarily decreases from the time point t1 due to the increase in the upshift side hydraulic pressure Pu from the time point t1, but returns to the target speed ratio γt at the time point t2 due to the increase in the downshift side hydraulic pressure to Pdc and the increase in the engine torque Te. . Also in this case, if the increase in the upshift side hydraulic pressure Pu due to the open stick generated in the oil flow control valve 40 is relatively low as shown by the dotted line Pus2 in FIG. 5, the downshift side hydraulic pressure Pd is the same. As indicated by the broken line in the figure, it may be left as it is without being particularly increased. This is that step 16 is substantially omitted.

  While the present invention has been described in detail with respect to several embodiments thereof, it will be apparent to those skilled in the art that various modifications can be made to these embodiments within the scope of the present invention. Let's go.

1 is a schematic diagram showing one embodiment of a shift control device for a disk / roller type continuously variable transmission according to the present invention. The flowchart which shows an example of the point which operates the speed-change control means by load torque control. The flowchart which shows an example of the point which controls the gear ratio of a disc / roller type continuously variable transmission with the transmission control apparatus of this invention. FIG. 4 is a graph showing changes in various parameters when the oil flow control valve 42 shown in FIG. 1 is stuck in an open state and the control proceeds to step 9 in the flowchart of FIG. 3. FIG. 4 is a graph showing changes in various parameters when the oil flow control valve 40 shown in FIG. 1 is stuck in an open state and the control proceeds to step 16 in the flowchart of FIG. 3.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10 ... Roller, 12 ... Trunnion, 14 ... Eccentric shaft, 16 ... Hydraulic actuator, 18 ... Piston, 20, 22 ... Hydraulic chamber, 24 ... Hydraulic cylinder, 26, 28 ... Port, 30 ... Shaft part, 32, 34 ... Piston Pressure receiving surface, 36 ... hydraulic pump, 38 ... oil reservoir, 40, 42 ... oil flow control valve, 44 ... oil supply port, 46 ... oil discharge port, 48 ... port in / out, 50 ... valve housing, 52 ... valve spool, 54 DESCRIPTION OF SYMBOLS ... Compression coil spring, 56 ... Electromagnetic drive device, 58 ... Oil supply port, 60 ... Oil discharge port, 62 ... In / out port, 64 ... Valve housing, 66 ... Valve spool, 68 ... Compression coil spring, 70 ... Electromagnetic drive device, 72 ... Shift control means

Claims (9)

  Displacement control means for controlling a displacement for changing the transmission ratio of the continuously variable transmission by controlling the torque of the load is a shift control device for a disk / roller type continuously variable transmission that drives a load by a power source. A speed change control device comprising:   Another displacement control means for controlling the displacement for changing the gear ratio of the continuously variable transmission, and the displacement control means by controlling the torque value of the load is connected to the other displacement control means. 2. The shift control device according to claim 1, wherein the shift control device is operated when a failure occurs that prevents normal operation.   The shift control device according to claim 2, wherein the other displacement control means is a hydraulic servo device.   The hydraulic servo apparatus includes a piston having a first pressure receiving surface for displacing the continuously variable transmission to a speed increasing side and a second pressure receiving surface for displacing the continuously variable transmission to a deceleration side; Hydraulic cylinders forming first and second hydraulic chambers for the first and second pressure receiving surfaces of the piston, and electromagnetically operated oil flow control for supplying and discharging hydraulic pressure to the first and second piston pressure receiving surfaces And a shift control means for controlling the operation of the oil flow control valve, and the oil flow control valve has the second piston pressure-receiving surface against the first piston pressure-receiving surface when energization is interrupted. 4. The transmission control apparatus according to claim 3, wherein a higher hydraulic pressure for the surface is maintained.   The oil flow control valve includes a first oil flow control valve that supplies and discharges hydraulic pressure to and from the first piston pressure receiving surface, and a second oil flow control valve that supplies and discharges hydraulic pressure to and from the second piston pressure receiving surface. And when the first and second oil flow control valves are de-energized, the hydraulic pressure that the first oil flow control valve holds against the first piston pressure receiving surface is the second oil flow control valve. 5. The speed change control device according to claim 4, wherein the oil flow control valve is configured to be higher than a hydraulic pressure held by the second piston pressure receiving surface.   The hydraulic servo apparatus includes a piston having a first pressure receiving surface for displacing the continuously variable transmission to a speed increasing side and a second pressure receiving surface for displacing the continuously variable transmission to a deceleration side; A hydraulic cylinder that forms first and second hydraulic chambers for the first and second pressure receiving surfaces of the piston; an oil flow control valve that supplies and discharges hydraulic pressure to and from the first and second piston pressure receiving surfaces; Shift control means for controlling the operation of the oil flow control valve, and when the oil flow control valve is fixed in a state of continuously supplying hydraulic pressure to the second piston pressure receiving surface, the second due to the fixation 4. The shift control device according to claim 3, wherein an output torque of the power source is reduced in response to an increase in oil pressure with respect to the piston pressure receiving surface.   The hydraulic servo device includes a first oil flow control valve that supplies and discharges hydraulic pressure to and from the first piston pressure receiving surface and a second oil flow control valve that supplies and discharges hydraulic pressure to and from the second piston pressure receiving surface. Including, when the second oil flow control valve is fixed in a state of continuously supplying oil pressure to the second piston pressure receiving surface, the first oil flow control valve supplies hydraulic pressure to the first piston pressure receiving surface. The shift control device according to claim 6, wherein the shift control device is configured to increase the speed.   The hydraulic servo apparatus includes a piston having a first pressure receiving surface for displacing the continuously variable transmission to a speed increasing side and a second pressure receiving surface for displacing the continuously variable transmission to a deceleration side; A hydraulic cylinder that forms first and second hydraulic chambers for the first and second pressure receiving surfaces of the piston; an oil flow control valve that supplies and discharges hydraulic pressure to and from the first and second piston pressure receiving surfaces; Shift control means for controlling the operation of the oil flow control valve, and when the oil flow control valve is fixed in a state of continuously supplying hydraulic pressure to the first piston pressure receiving surface, the first due to the fixation 4. The shift control device according to claim 3, wherein an output torque of the power source is increased in response to an increase in oil pressure with respect to the piston pressure receiving surface. The hydraulic servo device includes a first oil flow control valve that supplies and discharges hydraulic pressure to and from the first piston pressure receiving surface and a second oil flow control valve that supplies and discharges hydraulic pressure to and from the second piston pressure receiving surface. Including, when the first oil flow control valve is fixed in a state of continuously supplying oil pressure to the first piston pressure receiving surface, the second oil flow control valve supplies hydraulic pressure to the second piston pressure receiving surface. The shift control apparatus according to claim 8, wherein the shift control apparatus is configured to increase the speed.

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