JP2010014264A - Controller of variable displacement pump motor type transmission - Google Patents

Abstract

A control device for a variable displacement pump motor type transmission capable of improving the power transmission efficiency of a transmission at the highest speed stage.
Two differential mechanisms connected in parallel to a power source, two variable displacement pump motors for applying reaction torque or driving torque, and power transmission selectively by a switching mechanism with respect to an output member In a control device for a variable displacement pump motor type transmission having a plurality of shift speed transmission mechanisms to be enabled, the side opposite to the side where the transmission mechanism for the highest speed stage with the smallest speed ratio is provided A switching mechanism for the direct connection stage that selectively connects the reaction force element and the output element of the other differential mechanism, and the transmission mechanism for the highest speed stage that is capable of transmitting power to the output member; Direct coupling stage forming means for connecting the reaction force element of the other differential mechanism and the output element when the rotation speed of the reaction force element of the other differential mechanism is synchronized with the rotation speed of the output element (step S4). To S7).
[Selection] Figure 6

Description

  In the present invention, a power source such as an internal combustion engine is transmitted to an output member through a differential mechanism and a transmission mechanism for transmission, and a reaction torque is applied to the differential mechanism by a variable displacement pump motor. The present invention relates to a transmission control device capable of controlling the torque of a member.

  An example of this type of transmission is described in Patent Document 1. The transmission described in Patent Document 1 connects an engine to each of input elements in two sets of differential mechanisms, and connects a variable displacement hydraulic pump motor to reaction force elements in each differential mechanism. One of the hydraulic pump motors is a so-called double swing type that can change the extrusion volume in both positive and negative directions, and a synchronous coupling mechanism (for example, a synchronizer) is provided between the output element and the output member in each differential mechanism. And a plurality of gear pairs for gears that can selectively transmit torque (power) through the gears. Furthermore, these hydraulic pump motors are connected by a closed hydraulic circuit that connects discharge ports that discharge pressure oil in a so-called forward rotation state and suction ports that suck pressure oil.

  Accordingly, in the transmission described in Patent Document 1, the extrusion volume of each hydraulic pump motor is set to a predetermined volume, and a gear pair for shifting stage for setting adjacent shifting stages is set to the output member. By making the torque transmission possible, one of the hydraulic pump motors functions as a pump to generate hydraulic pressure, and the accompanying reaction force acts on the reaction force element in the one differential mechanism. In the differential mechanism, the torque from the power source acts on the input element, and the reaction force torque from the hydraulic pump motor acts on the reaction force element. It is output to the gear stage gear pair. And the torque amplified according to the gear ratio of the gear stage for the gear stage is transmitted to the output member.

  On the other hand, the other hydraulic pump motor functions as a motor when pressure oil is supplied via a hydraulic closed circuit, and the torque is transmitted to a reaction force element in the other differential mechanism. In the other differential mechanism, since the torque from the power source is input to the input element, the torque and the torque transmitted to the reaction element are combined, and the output element generates a predetermined gear stage gear pair. Is output. And the torque amplified according to the gear ratio of the gear stage for the gear stage is transmitted to the output member. That is, a torque obtained by synthesizing the torques transmitted through the two pairs of speed change gears appears on the output member. The torque changes in accordance with the ratio of torque transmitted via the hydraulic pressure, that is, the pump motor extrusion volume, so that the gear ratio can be continuously changed.

  Further, in the transmission described in Patent Document 1, if the extrusion volume of one of the pump motors is set to “0”, the flow of pressure oil in the closed hydraulic circuit is prevented, so that the other pump motor Locked. As a result, the reaction force element of the differential mechanism to which the pump motor is connected is fixed, so that the power output from the power source is transmitted to the output member via the differential mechanism and a predetermined gear stage gear pair. Communicated. Then, a fixed speed ratio (fixed speed) is set in accordance with the gear ratio of the speed change gear pair. Therefore, in this case, power transmission via hydraulic pressure does not occur, so that power transmission efficiency is relatively good.

JP 2007-64269 A

  As described above, in the transmission described in Patent Document 1, if the other pump motor is locked by setting the extrusion volume of one pump motor to “0”, the reaction force element in the other differential mechanism Is fixed, the power output from the power source is transmitted to the output member through the differential mechanism and a predetermined gear stage gear pair. This is so-called mechanical power transmission that does not convert the power into a hydraulic flow, so that the power transmission efficiency of the transmission is relatively good. With this mechanical power transmission state without good oil pressure with good power transmission efficiency, that is, with a fixed speed ratio (fixed speed) set, the output torque of the power source is obtained and the reaction torque is obtained from the hydraulic pump motor. If transmission can be performed directly to the output shaft side, that is, transmission to the output shaft side in a so-called direct connection state, the power transmission efficiency of the transmission will be even better.

  However, the transmission described in Patent Document 1 is not configured to transmit the output torque of the power source to the output shaft side in a directly connected state, and the power transmission of the transmission, particularly at a high speed stage. There was still room for improvement in order to improve efficiency.

  The present invention has been made by paying attention to the above technical problem, and can set a direct connection state without power transmission via hydraulic pressure, and improve the power transmission efficiency of the transmission in that state. An object of the present invention is to provide a control device for a variable displacement pump motor type transmission.

  In order to achieve the above object, the invention of claim 1 includes two differential mechanisms each having an input element connected in parallel to a power source and to which an output torque of the power source is input, Two variable displacement pump motors that are respectively connected to reaction force elements of the differential mechanism and selectively apply reaction force torque or drive torque, and discharge ports and suction ports of the variable displacement pump motors are mutually connected. A closed circuit formed by two oil passages communicating with the control unit, and a control mechanism that is provided between the output element and the output member of each differential mechanism and that can selectively transmit power by controlling the switching mechanism. And a variable displacement pump motor type transmission control device having a plurality of shift speed transmission mechanisms each having a different gear ratio, wherein the highest speed stage having the smallest speed ratio among the plurality of shift speed transmission mechanisms for A switching mechanism for a direct connection stage that selectively connects a reaction force element and an output element of the other differential mechanism on the opposite side to the one differential mechanism on the side on which the moving mechanism is provided, and the highest speed The stage transmission mechanism is set in a state where power can be transmitted to the output member, and the speed is changed to the highest speed stage, and the rotation speed of the reaction element of the other differential mechanism and the rotation speed of the output element are synchronized Alternatively, a variable capacitor comprising direct coupling stage forming means for controlling the direct coupling stage switching mechanism to connect the reaction element and the output element of the other differential mechanism when substantially synchronized with each other It is a control apparatus of a type pump motor type transmission.

  According to a second aspect of the present invention, in the first aspect of the present invention, a relief pressure that defines an upper limit of the hydraulic pressure in the closed circuit is set, and the hydraulic pressure in the closed circuit is discharged by being controlled to an open state. A variable pressure regulator, comprising: a means for controlling the pressure regulating valve to be opened when the direct coupling stage forming means connects the reaction force element and the output element of the other differential mechanism. It is a control apparatus of a capacity type pump motor type transmission.

  The invention according to claim 3 is the invention according to claim 1 or 2, wherein the direct connection stage forming means connects the reaction element and the output element of the other differential mechanism. A control device for a variable displacement pump motor type transmission, comprising means for controlling the switching mechanism provided on the mechanism side to a neutral state not engaged with any of the transmission gear mechanisms.

According to a fourth aspect of the present invention, in the invention according to any one of the first to third aspects, at least the other differential mechanism includes a ring gear, a sun gear, and a carrier as the input element, the reaction force element, and the output element, respectively. The planetary gear unit is provided on the opposite side of the gear ratio ρ between the ring gear and the sun gear, the speed ratio κ _{1 of the} transmission mechanism for the highest speed stage, and the transmission mechanism for the highest speed stage. The transmission ratio of the medium- and high-speed stage transmission mechanism that is in a state capable of transmitting power when the reaction force element and the output element of the other differential mechanism are connected by the direct connection stage forming means of the transmission stage transmission mechanism. kappa ₂ and is, so as to satisfy the relationship of _{"κ 1 × κ 2 ≦ {1} / (1 + ρ)} ", the other of the differential mechanism and the maximum speed for the transmission mechanism and said high speed stage power transmission mechanism Structure It is a control device for a variable capacity pump motor type transmission, characterized in being.

  According to a fifth aspect of the present invention, in any one of the first to fourth aspects, the input member to which the output torque of the power source is directly transmitted and the input element of the other differential mechanism can be integrally rotated. It is the control apparatus of the variable displacement pump motor type transmission which is connected.

  The invention according to claim 6 is characterized in that the input member to which the output torque of the power source is directly transmitted and the input element of the one differential mechanism are connected so as to be integrally rotatable. In any one of the inventions 4 to 4, the control device for the variable displacement pump motor type transmission.

  According to the invention of claim 1, when setting the highest speed stage of the transmission, that is, when upshifting to the highest speed stage, the other differential mechanism on the side where the transmission mechanism for the highest speed stage is not installed. The number of revolutions of the reaction force element and the number of revolutions of the output element are compared. If the number of revolutions is the same or almost the same, that is, the rotation of the reaction force element and the output element of the other differential mechanism is synchronized or almost synchronized. In this case, the direct connection stage switching mechanism is controlled, and the reaction force element and the output element of the other differential mechanism are connected to rotate integrally. As a result, all the rotating elements of the other differential mechanism are rotated together. That is, the input element and the output element of the other differential mechanism rotate together, and the power source and the output member are directly connected. Therefore, when setting the highest speed stage of the transmission, together with the highest speed stage set by the transmission mechanism for the highest speed stage, it is possible to form a so-called direct connection stage in which the power source and the output member are directly connected. The output torque of the power source can be directly transmitted to the output member. In other words, when setting the highest speed stage of the transmission, the output torque of the power source is directly transmitted to the output member via the other differential mechanism without requiring the reaction torque from the variable displacement pump motor. be able to.

  Therefore, the transmission of power from the power source to the output member in the state where the maximum speed stage is set is used for the flow of pressure oil between the variable displacement pump motors and the generation of reaction torque in the variable displacement pump motors. It can be performed only through the other differential mechanism and the transmission gear transmission mechanism without requiring hydraulic pressure, and is closed by not requiring hydraulic pressure to generate pressure oil flow or reaction torque. Loss such as hydraulic leakage in the circuit can be reduced, and as a result, power transmission efficiency at the highest speed stage of the transmission can be improved.

  In addition, the coupling between the reaction force element of the other differential mechanism and the output element by the switching mechanism for the direct coupling stage is performed in a state in which the rotation of the reaction force element and the output element is synchronized or almost synchronized. The synchronous coupling function required for the switching mechanism becomes unnecessary or can be reduced. For example, a dog clutch having a high power transmission efficiency or a small-capacity synchronizer can be employed as the direct coupling stage switching mechanism. By forming the direct connection stage as described above at the highest speed stage, the torque input from the output member side can be directly transmitted to the power source even when the direct connection stage is set at the highest speed stage. it can.

  According to the invention of claim 2, when the highest speed stage of the transmission is set and the power source and the output member are brought into a direct connection state, the pressure regulating valve is opened so that the variable displacement pump motors are mutually connected. The hydraulic pressure in the closed circuit that is in communication is discharged. As a result, when the direct connection stage is set at the highest speed stage, the hydraulic pressure is not applied to each variable displacement pump motor, that is, each variable displacement pump motor can be brought into a free state capable of idling. Therefore, the reaction force torque is generated by applying hydraulic pressure to the power transmission path from the power source to the output member through the other differential mechanism and the transmission gear mechanism in the direct connection stage, and any one of the variable displacement pump motors. Interference with the normal power transmission path when it is generated can be avoided.

  According to the invention of claim 3, when the highest speed stage of the transmission is set and the power source and the output member are brought into a direct connection state, one differential mechanism side, that is, the transmission mechanism for the highest speed gear stage. The switching mechanism on the side where is provided is brought into a so-called neutral state that does not engage with any of the shift speed switching mechanisms. That is, any of the transmission gears arranged on the one differential mechanism side is in a state in which power transmission is interrupted with respect to the power source, the differential mechanism, and the output member. Therefore, power transmission between the power source and the variable displacement pump motor on one differential mechanism side, that is, the transmission mechanism side for the highest speed shift stage, can be cut off with the direct connection stage set at the highest speed stage. The occurrence of loss due to dragging the variable displacement pump motor can be avoided.

Further, according to the invention of claim 4, when setting the direct coupled stage at the maximum speed stage of the transmission, the transmission ratio of the transmission is set based on the gear ratio kappa ₁ fastest stage power transmission mechanism gear When the ratio is equal to or substantially equal, the rotation of the reaction force element and the output element of the other differential mechanism is synchronized or substantially synchronized. Therefore, in the state where the highest speed stage of the transmission is set by the transmission mechanism for the highest speed stage, the reaction force element and the output element of the other differential mechanism can be connected to form a direct connection stage. In other words, the gear ratio of the transmission becomes the gear ratio at the highest speed by the transmission mechanism for the highest gear or the gear ratio substantially equal thereto, and at the same time the rotation of the reaction force element and the output element of the other differential mechanism These reaction force elements and the output elements can be connected to form a direct coupling stage by synchronizing or substantially synchronizing them.

  According to the invention of claim 5, since the output torque of the power source is directly transmitted to the other differential mechanism side to which power is input when forming the direct coupling stage, the direct coupling stage is set in a state where the direct coupling stage is set. The power transmission efficiency of the transmission can be improved.

  According to the sixth aspect of the present invention, one differential mechanism side to which power is input when forming the highest speed stage by the highest speed stage transmission mechanism, that is, the side on which the highest speed stage transmission mechanism is provided. Since the output torque of the power source is directly transmitted to the power source, it is possible to improve the power transmission efficiency of the transmission in the state where the highest speed stage is set by the transmission mechanism for the highest speed stage.

  Next, the present invention will be described based on specific examples. First, the transmission targeted by the present invention will be described. The transmission targeted by the present invention is provided with at least two power transmission systems, and an output member from a power source via both power transmission systems. Thus, the transmission can continuously change the speed ratio, which is the ratio of the rotational speeds of the power source and the output member. More specifically, each power transmission system includes a variable displacement hydraulic pump motor that functions as both a pump and a motor, and is configured to transmit torque according to its extrusion volume, and further each variable transmission system. The capacity type hydraulic pump motor communicates with each other so as to exchange pressure oil with each other. Therefore, when one of the variable displacement hydraulic pump motors functions as a pump, torque corresponding to the extrusion volume is transmitted from the power source to the output member, and at the same time, from one variable displacement hydraulic pump motor to the other variable displacement. Pressure oil is supplied to the mold hydraulic pump motor, and the other variable displacement hydraulic pump motor functions as a motor. That is, power transmission via pressure oil is performed in parallel. The torque is transmitted to the output member via the other power transmission system. As a result, the torque transmitted to the output member is the sum of the torque transmitted via each power transmission system, and the torque transmitted via the pressure oil changes according to each extrusion volume. Eventually, the gear ratio changes continuously.

  Each power transmission system can be equipped with a gear transmission mechanism such as a gear pair and a winding transmission mechanism with different gear ratios, and when transmitting torque to the output member via only one power transmission system. The transmission ratio of the transmission as a whole is determined by the transmission ratio of the transmission gear mechanism in the power transmission system. If such a gear ratio is referred to as a fixed gear ratio, transmission of power via pressure oil does not occur in a state where the fixed gear ratio is set, so that power loss is unlikely to occur and an efficient transmission state. It becomes. In order to allow only one of the gear transmission mechanisms to participate in torque transmission, it is preferable that a switching mechanism such as a clutch mechanism is included in each gear transmission mechanism, or a power source or an output member It is preferable to provide a switching mechanism between the gear stage transmission mechanism.

  Since the transmission targeted by the present invention is configured to transmit power via pressure oil, the hydrostatic mechanical having the function of setting the gear ratio by mechanical power transmission as described above -Preferably configured as a transmission (HMT). The mechanical transmission portion can be appropriately configured as necessary, and a mechanism of selecting a gear pair that is always meshed by a switching mechanism such as a clutch mechanism or a synchronous coupling mechanism, or a plurality of planetary gear mechanisms. Or the structure etc. which can set a some gear ratio with a compound planetary gear mechanism are employable. Further, the variable displacement hydraulic pump motor may be configured to use a variable displacement hydraulic pump motor as a reaction force means in addition to the configuration in which the variable displacement hydraulic pump motor is interposed in series between the power source and the output member.

  Next, a specific example will be described in which a differential mechanism is used as a power distribution mechanism and a plurality of gear pairs are used as transmission gear transmission mechanisms, and therefore a variable displacement hydraulic pump motor is a reaction force mechanism. The example shown in FIG. 1 is an example configured as a transmission TM for a vehicle. As a so-called fixed speed ratio (or fixed speed) that can be set by transmitting torque without using hydraulic oil, four forward speeds and 1 In this example, two reverse gears are set. That is, an input member 2 is connected to an internal combustion engine (hereinafter referred to as an engine) 1 such as a gasoline engine or a diesel engine as a power source, and the first planetary gear corresponding to the differential mechanism in the present invention is connected to the input member 2. Torque is transmitted to the mechanism 3 and the second planetary gear mechanism 4. Appropriate transmission means such as a damper, a clutch, a torque converter, or the like may be interposed between the engine 1 and the input member 2.

  In the example shown in FIG. 1, the second planetary gear mechanism 4 is disposed on the same axis as the input member 2, and the first planetary gear mechanism 3 is separated outward in the radial direction of the second planetary gear mechanism 4. They are arranged in parallel with their central axes parallel. These planetary gear mechanisms 3 and 4 can use planetary gear mechanisms of an appropriate type such as a single pinion type and a double pinion type. The example shown in FIG. 1 is an example constituted by a single pinion type planetary gear mechanism, and is a sun gear 3S, 4S that is an external gear, and a ring gear 3R that is an internal gear arranged concentrically with the sun gear 3S, 4S. , 4R and carriers 3C, 4C holding pinion gears meshed with these sun gears 3S, 4S and ring gears 3R, 4R so as to be rotatable and revolved. The input member 2 is connected to the ring gear 4R in the second planetary gear mechanism 4, and the ring gear 4R serves as an input element.

  Further, a counter drive gear 5 is attached to the input member 2, and an idle gear 6 is engaged with the counter drive gear 5, and a counter driven gear 7 is engaged with the idle gear 6. The counter driven gear 7 is disposed on the same axis as the first planetary gear mechanism 3 and is connected to the ring gear 3R of the first planetary gear mechanism 3 so as to rotate together. Therefore, in the first planetary gear mechanism 3, the ring gear 3R is an input element. The ring gears 3R and 4R, which are input elements of the planetary gear mechanisms 3 and 4, are configured so that the counter gear pair includes the idle gear 6, and thus rotate in the same direction.

  Of the planetary gear mechanisms 3 and 4, the carrier 3C in one of the first planetary gear mechanisms 3 is an output element, and a first intermediate shaft 8 as a rotating shaft rotates integrally with the carrier 3C. So that they are connected. The first intermediate shaft 8 is a hollow shaft into which a motor shaft 9 is rotatably inserted. One end of the motor shaft 9 is a sun gear that is a reaction force element in the first planetary gear mechanism 3. It is connected to 3S so as to rotate together.

  On the other hand, the other second planetary gear mechanism 4 has the same configuration, and the carrier 4C serves as an output element, and the second intermediate shaft 10 as another rotating shaft is integrated with the carrier 4C. Are connected to rotate. The second intermediate shaft 10 is a hollow shaft, and a motor shaft 11 is rotatably inserted therein. One end of the motor shaft 11 is a sun gear that is a reaction force element in the second planetary gear mechanism 4. 4S is connected to rotate integrally.

  The other end of the motor shaft 9 is connected to the output shaft of the variable displacement pump motor 12. The variable displacement pump motor 12 is a hydraulic pump capable of changing a discharge capacity (or extrusion volume) such as a slant shaft pump, a swash plate pump, or a radial piston pump, and rotates the output shaft by applying torque. By functioning as a pump, the pressure oil is discharged, and the pressure oil is supplied from the discharge port or the suction port, thereby functioning as a motor. In the following description, the variable displacement pump motor 12 is referred to as a first pump motor 12 and is represented as PM1 in the drawing.

  The first pump motor 12 is provided with a capacity changing mechanism for controlling the extrusion volume. This capacity changing mechanism has a function of changing the inclination angle of the oblique shaft or swash plate or changing the relative eccentricity of the rotor in the radial piston pump. For example, the hydraulic pressure is discharged according to the duty ratio. The main component is a solenoid valve (not shown).

  On the other hand, the other end of the motor shaft 11 is connected to the output shaft (rotor) of the variable displacement pump motor 13. The variable displacement pump motor 13 has the same configuration as the first pump motor 12 on the motor shaft 9 side, and therefore, the discharge capacity of an oblique shaft pump, a swash plate pump, a radial piston pump, or the like can be changed. A hydraulic pump can be employed. In the following description, the variable displacement pump motor 13 is referred to as a second pump motor 13 and is indicated as PM2 in the figure.

  Similar to the first pump motor 12, the second pump motor 13 is provided with a capacity changing mechanism for controlling the extrusion volume. This capacity changing mechanism has a function of changing the inclination angle of the oblique shaft or swash plate or changing the relative eccentricity of the rotor in the radial piston pump. For example, the hydraulic pressure is discharged according to the duty ratio. The main component is a solenoid valve (not shown).

  The pump motors 12 and 13 are communicated with each other by two oil passages 14 and 15 so that the pressure oil, which is a pressure fluid, can be transferred to each other. That is, the suction ports 12S and 13S are communicated with each other by the oil passage 14, and the discharge ports 12D and 13D are communicated with each other through the oil passage 15. Therefore, a closed circuit CC is formed by the oil passages 14 and 15. A mechanism for hydraulic control in the closed circuit CC will be described later. In the example shown in FIG. 1, when a vehicle equipped with the transmission TM shown in FIG. 1 is driven by the power of the engine 1, one of the pump motors 12 (or 13) rotates in the reverse direction, and its suction port 12S. (Or 13S) is configured to discharge the pressure oil.

  An output shaft 16 corresponding to the output member of the present invention is arranged in parallel with each of the intermediate shafts 8 and 10 described above. A gear stage transmission mechanism for setting a predetermined gear ratio is provided between the output shaft 16 and each of the intermediate shafts 8 and 10. The transmission gear transmission mechanism according to the present invention is not limited to a mechanism that transmits power at a fixed rotation speed ratio (transmission ratio), and a mechanism with a variable transmission ratio can be employed. In the example shown in FIG. A plurality of gear pairs 17, 18, 19, and 20 that transmit power at a fixed gear ratio are employed.

  More specifically, a fourth speed drive gear 17A and a second speed drive gear 18A are disposed on the first intermediate shaft 8 in this order from the first planetary gear mechanism 3 side. The drive gear 17 </ b> A and the second speed drive gear 18 </ b> A are rotatably fitted to the first intermediate shaft 8. A fourth speed driven gear 17B meshed with the fourth speed drive gear 17A and a second speed driven gear 18B meshed with the second speed drive gear 18A are attached to rotate integrally with the output shaft 16. ing.

  Further, the third speed drive gear 19A meshed with the fourth speed driven gear 17B and the first speed drive gear 20A meshed with the second speed driven gear 18B are rotatable on the second intermediate shaft 10. It is made to fit. Accordingly, the fourth speed driven gear 17B also serves as the third speed driven gear, and the second speed driven gear 18B also serves as the first speed driven gear. Here, the rotational speed ratio or gear ratio of each gear pair 17, 18, 19, 20 (ratio of the number of teeth of the driven gear to the number of teeth of each drive gear) will be described. The gear pair 20 for the second gear, the gear pair 18 for the second speed, the gear pair 19 for the third speed, and the gear pair 17 for the fourth speed are configured to become smaller in this order. Therefore, among the gear pairs 20, 18, 19, 17 as the gear stage transmission mechanism in the present invention, the fourth speed gear pair 17 having the smallest speed ratio corresponds to the maximum speed stage transmission mechanism in the present invention. is doing.

  Furthermore, a starting gear pair 21 is provided. The starting gear pair 21 is for transmitting the power to the output shaft 16 together with the first speed gear pair 20 so as to increase the driving force at the time of starting sufficiently and sufficiently. A start drive gear 21A attached to the motor shaft 9 on the motor 12 side so as to rotate integrally therewith, and a start driven gear 21B attached to the output shaft 16 so as to be rotatable.

  A switching mechanism is provided for allowing each of the gear pairs 17, 18, 19, 20, and 21 described above to transmit torque between any of the intermediate shafts 8 and 10 and the output shaft 16. In short, this switching mechanism is a coupling mechanism that selectively transmits torque, and a conventionally known mechanism such as a dog clutch mechanism or a synchronous coupling mechanism (synchronizer or synchromesh mechanism) can be employed. FIG. 1 shows an example in which a synchronizer is employed.

  The synchronizer basically has a sleeve that rotates together with a rotating shaft, a spline that is provided on another rotating member that rotates relative to the rotating shaft, and is moved by the sleeve toward the other rotating member. And synchronizer ring. Then, in the process of moving the sleeve to the spline side of the other rotating member, the synchronizer ring gradually makes frictional contact with the rotating member to synchronize the rotating shaft and the rotating member, and in this state, the sleeve engages with the spline. The rotating shaft and the rotating member are connected to each other. On the output shaft 16, a start synchronizer (hereinafter referred to as S synchro) 22 is provided at a position adjacent to the start driven gear 21B. The S synchro 22 is brought into an engaged state by moving the sleeve 22S to the left side in FIG. 1, and the starter driven gear 21B is connected to the output shaft 16, and the starter gear pair 21 is connected to the motor shaft 9 and the output shaft. 16 is configured to transmit torque. Further, the sleeve 22S is moved to the right side in FIG. 1 to be in a released state, and the connection between the start driven gear 21B and the output shaft 16 is released.

  A first synchronizer (hereinafter referred to as a first synchronizer) 23 is provided between the third speed drive gear 19A and the first speed drive gear 20A on the second intermediate shaft 10 described above. The first sync 23 is brought into an engaged state by moving the sleeve 23S to the left side in FIG. 1 to connect the first speed drive gear 20A to the second intermediate shaft 10 and to connect the first speed gear pair 20. Is configured to transmit torque between the second intermediate shaft 10 and the output shaft 16. On the other hand, by moving the sleeve 23S to the right side in FIG. 1, another engagement state is established, and the third speed drive gear 19A is connected to the second intermediate shaft 10, and the third speed gear pair 19 is connected. Torque is transmitted between the second intermediate shaft 10 and the output shaft 16. Then, the sleeve 23S is placed in the center to be in the released state, and the third speed drive gear 19A, the first speed drive gear 20A and the second intermediate shaft 10 are disconnected.

  Further, a second synchronizer (hereinafter referred to as a second synchronizer) 24 is provided on the first intermediate shaft 8 between the second speed drive gear 18A and the fourth speed drive gear 17A. The second sync 24 is brought into an engaged state by moving the sleeve 24S to the left side in FIG. 1 to connect the second speed drive gear 18A to the first intermediate shaft 8 and to connect the second speed gear pair 18. Is configured to transmit torque between the first intermediate shaft 8 and the output shaft 16. On the other hand, by moving the sleeve 24S to the right side in FIG. 1, the engagement state is established, and the fourth speed drive gear 17A is connected to the first intermediate shaft 8 so that the fourth speed gear pair 17 is connected. Torque is transmitted between the first intermediate shaft 8 and the output shaft 16. Then, the sleeve 24S is positioned in the center to be in the released state, and the second speed driving gear 18A and the fourth speed driving gear 17A are disconnected from the first intermediate shaft 8.

  Furthermore, a reverse gear synchronizer (hereinafter referred to as “R synchro”) 25 is provided on the motor shaft 11 on the second pump motor 13 side at a position adjacent to the shaft end of the second intermediate shaft 10. The R synchro 25 is brought into an engaged state by moving the sleeve 25S to the right in FIG. 1, and the motor shaft 11 and the second intermediate shaft 10, that is, the sun gear 4S and the carrier 4C in the second planetary gear mechanism 4 Are connected to rotate the entire second planetary gear mechanism 4 integrally. Therefore, the R synchro 25 is the second planetary gear mechanism on the side opposite to the first planetary gear mechanism 3 on the side where the above-described fourth speed gear pair 17, that is, the highest speed stage transmission mechanism in the present invention is provided. The four reaction force elements (sun gear 4S) and the output element (carrier 4C) are selectively connected to each other and correspond to the direct coupling stage switching mechanism in the present invention. In other words, this R sync 25 is a sync for the reverse gear operated when setting the reverse gear and a sync corresponding to the switching mechanism for the direct gear according to the present invention operated when setting the direct gear described later. And both. Therefore, the direct connection stage switching mechanism according to the present invention only has to use the R synchro 25 provided for the reverse stage, and there is no need to provide a direct connection stage sync or the like. Therefore, the direct coupling stage switching mechanism can be configured with a simple configuration without complicating the structure of the transmission TM.

  Each of the synchros 22, 23, 24, and 25 can be configured to be switched by manual operation, but can be configured to perform so-called automatic control instead. In that case, for example, an appropriate actuator (not shown) for moving each of the sleeves 22S, 23S, 24S, and 25S described above in the axial direction may be provided, and the actuator may be electrically controlled.

  As described above, the transmission TM shown in FIG. 1 is configured such that the torque output from the engine 1 is transmitted to the output shaft 16 via any one of the intermediate shafts 8 and 10 or the motor shafts 9 and 11. ing. A differential 27 is connected to the output shaft 16 via a transmission device 26 such as a gear transmission mechanism or a winding transmission mechanism using a chain and a sprocket, from which power is output to the left and right axles 28. ing.

  Further, a sensor for detecting the operating state of the transmission TM is provided. Specifically, the input rotational speed sensor 29 for detecting the rotational speed Nin (or the engine rotational speed Ne) of the input member 2 or the counter drive gear 5 integrated therewith, and the rotational speed Nout of the axle 31 are detected. The output speed sensor 30, the output shaft (rotor) of the first pump motor 12, that is, the first pump motor speed sensor 31 that detects the speed Npm1 of the motor shaft 9, and the output shaft (rotor) of the second pump motor 13, that is, the motor A second pump motor rotational speed sensor 32 for detecting the rotational speed Npm2 of the shaft 11 is provided.

  Next, a hydraulic circuit for controlling each of the pump motors 12 and 13 will be described. A closed circuit CC that communicates the pump motors 12 and 13 is provided with a charge pump (sometimes referred to as a boost pump) 33 for supplying oil (operating oil). The charge pump 33 is for compensating for the shortage of oil due to leakage from the closed circuit CC. The charge pump 33 is driven by the engine 1 or a motor (not shown) to pump oil from the oil pan 34. It supplies to the closed circuit CC.

  The discharge port of the charge pump 33 communicates with the oil passage 14 and the oil passage 15 in the closed circuit CC via check valves 35 and 36, respectively. In addition, these check valves 35 and 36 are comprised so that it may open in the discharge direction from the charge pump 33, and may close in the opposite direction. Further, a relief valve 37 for adjusting the discharge pressure of the charge pump 33 is communicated with the discharge port of the charge pump 33. The relief valve 37 is opened when a pressure higher than the sum of the elastic force by the spring and the pressing force by the output pressure of the solenoid valve (not shown) is applied (set pressure, that is, pressure exceeding the relief pressure). Accordingly, the discharge pressure of the charge pump 33 is set to a pressure corresponding to the pilot pressure.

  Further, a relief valve 38 is provided between the suction port 12 </ b> S of the first pump motor 12 and the oil passage 15. In other words, the relief valve 38 is provided in parallel with the first pump motor 12 so as to communicate the oil passages 14 and 15. The relief valve 38 is configured to maintain the discharge pressure at a preset pressure when pressure oil is discharged from the suction port 12S of the first pump motor 12 or the suction port 13S of the second pump motor 13. Yes. That is, the relief valve 38 is configured to set a pressure regulation value (that is, a set pressure or a relief pressure) by a solenoid (not shown) attached thereto. When the discharge pressure exceeds the relief pressure, the relief valve 38 is opened and discharged to maintain the discharge pressure, that is, the pressure in the high-pressure side oil passage 14 below the relief pressure. Further, the relief valve 38 has a function of forcibly discharging the hydraulic pressure in the closed circuit CC by being controlled to an open state (OFF state) separately from the function of maintaining the relief pressure.

  On the other hand, a relief valve 39 is provided between the discharge port 13 </ b> D of the second pump motor 13 and the oil passage 14. In other words, the relief valve 39 is provided in parallel with the second pump motor 13 so as to communicate the oil passages 14 and 15. The relief valve 39 is configured to maintain the discharge pressure at a preset pressure when pressure oil is discharged from the discharge port 13D of the second pump motor 13 or the discharge port 12D of the first pump motor 12. Yes. That is, the relief valve 39 is configured to set a pressure regulation value (that is, set pressure, relief pressure) by a solenoid (not shown) attached to the relief valve 39, and the relief valve 39 from any one of the discharge ports 12D and 13D. When the discharge pressure exceeds the relief pressure, the relief valve 39 is opened and discharged to maintain the discharge pressure, that is, the pressure in the oil passage 15 below the relief pressure. Further, like the above-described relief valve 38, the relief valve 39 is controlled to an open state (OFF state) separately from the function of maintaining the relief pressure, thereby forcing the hydraulic pressure in the closed circuit CC. It also has a function to exhaust pressure.

  Therefore, the relief valve 38 and the relief valve 39 set a relief pressure that defines the upper limit of the hydraulic pressure in the closed circuit CC, and discharge the hydraulic pressure in the closed circuit CC by being controlled to an open state. This corresponds to the pressure regulating valve in the present invention.

  The transmission TM is configured to be able to electrically control the extrusion volume of the pump motors 12 and 13 and the synchros 22, 23, 24 and 25 or the relief valves 38 and 39. A control device (ECU) 40 is provided. The electronic control unit 40 is mainly composed of a microcomputer, and is inputted with the number of rotations of a predetermined rotating member and other detection signals, and the inputted signals and information stored in advance. In addition, the calculation is performed based on the program, and the command signal is output according to the calculation result. For example, the detection signals of the rotation speed sensors 29, 30, 31, and 32 are input to the electronic control unit 40, and the pump motors 12 and 13 and the synchros 22 are based on the calculation results based on the detection signals. , 23, 24, 25, the relief valves 38, 39, etc., command signals for controlling the operating state and the operating state are output from this electronic control unit 40.

  The transmission TM serves as a power transmission system for transmitting the power of the engine 1 to the output shaft 16, and the first planetary gear mechanism 3 and the fourth speed gear pair 17 to which a reaction force is applied by the first pump motor 12 or A path for transmitting power to the output shaft 16 via the second speed gear pair 18 and the second planetary gear mechanism 4 and the third speed gear pair 19 or the first speed to which a reaction force is applied by the second pump motor 13. There are two paths including a path for transmitting power to the output shaft 16 through the gear pair 20. And the torque transmitted via each power transmission path changes according to the extrusion volume of pump motors 12 and 13 provided in each.

  Next, the operation of the transmission TM described above will be described. FIG. 2 is a chart collectively showing the operation states of the pump motors (PM1, PM2) 12, 13 and the synchros 22, 23, 24, 25 when setting the respective gear positions. “0” for each of the pump motors 12 and 13 sets the pump capacity to the minimum or substantially “0” (zero), and does not generate pressure oil even when the output shaft (rotor) is rotated. In addition, the output shaft does not rotate even when hydraulic pressure is supplied (free state or idling state), and “LOCK” indicates the state where the rotation of the rotor is stopped. “PUMP” indicates a state in which the pump capacity is made larger than substantially zero and the pressure oil is discharged, and thus the corresponding pump motor 12 (or 13) functions as a pump. “MOTOR” indicates a state in which pressure oil discharged from one of the pump motors 12 (or 13) is supplied and functions as a motor. Therefore, the corresponding pump motor 13 (or 12) generates shaft torque. The driving torque is transmitted to the corresponding motor shaft 11 (or 9) and intermediate shaft 10 (or 8). Further, “FREE” indicates a state in which the rotors of the pump motors 12 and 13 are free (can be idled) by turning off the relief valves 38 and 39 and exhausting the hydraulic pressure in the closed circuit CC. Yes.

  And "right" and "left" about each synchro 22,23,24,25 show the position in FIG. 1 of each sleeve 22S, 23S, 24S, 25S in each synchro 22,23,24,25. In addition, parentheses indicate a standby state for downshifting, square brackets indicate a standby state for upshifting, and “N” indicates that the corresponding synchros 22, 23, 24, 25 are in an OFF state (neutral position, neutral). “N” in the neutral state set to) indicates the state in which drag is reduced by setting the corresponding synchros 22, 23, 24, 25 to the OFF state.

  When the neutral position is selected and the neutral (N) state is set, the pump motors 12 and 13 are turned off, and the sleeves 22S, 23S, 24S and 25S of the synchros 22, 23, 24 and 25 are turned on. Both are set at the center position. Therefore, none of the gear pairs 17, 18, 19, 20, 21 is in a neutral state that is not connected to the output shaft 16. That is, the pump motors 12 and 13 are controlled so that the extrusion volume (pump capacity) becomes substantially zero. As a result, a so-called idling state is established, so that even if torque is transmitted from the engine 1 to the ring gears 3R, 4R of the planetary gear mechanisms 3, 4, no reaction force acts on the sun gears 3S, 4S. Therefore, torque is not transmitted to the intermediate shafts 8 and 10 connected to the carriers 3C and 4C that are output elements.

  When the shift position is switched to a travel position such as a drive position, the sleeve 22S of the S synchro 22 is moved to the left in FIG. 1, and the sleeve 23S of the first sync 23 is moved to the left in FIG. Accordingly, the start drive gear 21A is connected to the motor shaft 9 to connect the first pump motor 12 and the output shaft 16, and the first speed drive gear 20A is connected to the second intermediate shaft 10 to be the second planetary gear. The carrier 4C, which is an output element of the mechanism 4, and the output shaft 16 are connected. That is, the first speed that is the fixed gear ratio is set. At the same time, the extrusion volume of each pump motor 12, 13 is controlled to be larger than zero.

  Therefore, the second pump motor 13 in this case is driven by the power of the engine 1 distributed by the second planetary gear mechanism 4 and functions as a pump. Therefore, the second pump motor 13 gives reaction force torque accompanying generation of hydraulic pressure to the motor shaft 11 and the sun gear 4S. This state is described as “POMP” in FIG. Therefore, the torque is transmitted to the carrier 4C by the differential action of the second planetary gear mechanism 4, and the torque is transmitted to the output shaft 16 via the first speed gear pair 20.

  On the other hand, the hydraulic pressure generated by the second pump motor 13 is discharged from the suction port 13S and supplied to the suction port 12S of the first pump motor 12. As a result, the first pump motor 12 functions as a motor. This is described as “MOTOR” in FIG. In this way, the power transmitted to the first pump motor 12 is transmitted to the output shaft 16 via the starting gear pair 21. Therefore, in the driving state from the start to the first speed, both so-called mechanical power transmission via the second planetary gear mechanism 4 and power transmission via the hydraulic pressure are generated, and the combined power of these powers is generated. Appears on the output shaft 16. Further, the gear ratio in this process becomes a value larger than the first speed which is a fixed gear ratio, and the gear ratio changes continuously or steplessly.

  When the rotational speed of the engine 1 and the vehicle speed change in this way to the first speed gear ratio, the extrusion volume of the first pump motor 12 is set to zero and turned off (indicated as “0” in FIG. 2). In addition, the extrusion volume of the second pump motor 13 is set to the maximum, and as a result, the rotation of the second pump motor 13 is substantially locked (indicated as “LOCK” in FIG. 2). That is, the motor shaft 11 and the second pump motor 13 connected thereto are fixed. As a result, the sun gear 4S of the second planetary gear mechanism 4 is fixed, and the first planetary gear mechanism 3 is not involved in the transmission of power to the output shaft 16, so that the power output from the engine 1 is the second planetary gear mechanism. 4 and the first speed gear pair 20 are transmitted to the output shaft 16. That is, a fixed gear ratio determined by the gear ratio of the first speed gear pair 20 is set. In this case, since the first pump motor 12 and the motor shaft 9 connected thereto are idled, no torque appears on the first intermediate shaft 8. If the sleeve 22S of the S synchronizer 22 and the sleeve 24S of the second synchronizer 24 are brought into the released state (OFF state) at the first speed which is the fixed gear ratio, the first pump motor 12 and the second pump motor 13 are rotated together. Since there is nothing, power loss can be prevented. Further, if the sleeve 24S of the second synchro 24 is moved to the left side in FIG. 1, it will be in an upshift standby state to the second speed.

  When upshifting from the first speed which is the fixed gear ratio, the sleeve 24S of the second synchro 24 is moved to the left side in FIG. 1 to connect the second speed drive gear 18A to the first intermediate shaft 8. The R synchro 25 is kept in a neutral state. In addition, when the sleeve 24S of the second synchro 24 is engaged with the second speed drive gear 18A, synchronous control is performed so that the rotation speed of the sleeve 24 of the second synchro 24 matches the rotation speed of the second speed drive gear 18A. . The synchronization control is similarly performed when the sleeves 22S, 23S, 24S, and 25S of the synchros 22, 23, 24, and 25 are engaged with the mating members.

  In this state, the extrusion volume of the first pump motor 12 is gradually increased toward the maximum. In the standby state for upshifting to the second speed, the first pump motor 12 rotates in the reverse direction, and thus functions as a pump by gradually increasing the extrusion volume. That is, the hydraulic pressure is generated (denoted as “PUMP” in FIG. 2), and at the same time, the reaction torque associated therewith appears on the motor shaft 9. As a result, transmission of power through the first planetary gear mechanism 3 and the second speed gear pair 18 is gradually performed. In addition, since the hydraulic pressure generated by the first pump motor 12 is supplied to the second pump motor 13 and functions as a motor (indicated as “MOTOR” in FIG. 2), the second pump motor 13 and the second planetary gears. Power is transmitted through the mechanism 4 and the first speed gear pair 20. Therefore, the speed ratio in the process of shifting from the first speed to the second speed is a value between the speed ratio of the first speed and the speed ratio of the second speed and is a continuously changing speed ratio. . That is, a continuously variable transmission state in which the gear ratio continuously changes is obtained. This is the same during the period from the start to the first speed ratio and between the fixed speed ratios. Therefore, the above-described transmission TM can function as a continuously variable transmission TM. it can.

  The motor shaft 9 is substantially fixed by making the extrusion volume of the first pump motor 12 substantially maximum as described above and stopping its rotation or becoming nearly stopped. In addition, the second pump motor 13 is set to the OFF state. Therefore, in the first planetary gear mechanism 3, since the sun gear 3S is fixed, the power input to the ring gear 3R is output from the carrier 3C to the second speed drive gear 18A via the intermediate shaft 8. On the other hand, the second pump motor 13 is in the OFF state, and the R synchro 25 and the first synchro 23 arranged coaxially therewith are in the OFF state, and the sleeve 25S and the sleeve 23S are in the neutral position. Therefore, the second pump motor 13 and the second planetary gear mechanism 4 are not involved in power transmission. Accordingly, the second speed, which is a fixed gear ratio determined by the gear ratio of the second speed gear pair 18, is set.

  Similarly, in the third speed, the sleeve 23S of the first synchronizer 23 is moved to the right in FIG. 1 so that the third speed drive gear 19A is connected to the second intermediate shaft 10, and the second pump By maximizing the extrusion volume of the motor 13, the motor shaft 11 and the second pump motor 13 are fixed and the other synchros 22, 24, and 25 are released as in the case of the first speed. . Accordingly, the power is transmitted to the output shaft 16 via the third speed gear pair 19, and the third speed, which is a fixed gear ratio, is set. Further, in the fourth speed, the sleeve 24S of the second synchro 24 is moved to the right in FIG. 1 so that the fourth speed drive gear 17A is connected to the first intermediate shaft 8, and the first pump motor 12 is pushed out. By maximizing the volume, as in the case of the second speed, the motor shaft 9 and the first pump motor 12 are fixed, and the other synchros 22, 23, 25 are released. Therefore, power is transmitted to the output shaft 16 via the fourth speed gear pair 17, and the fourth speed, which is the fixed gear ratio and the highest speed stage in the transmission TM, is set.

  The so-called direct coupling stage, which is a feature of the present invention, will be described. The direct coupling stage in the transmission TM is a speed ratio equivalent to the speed ratio at the highest speed, that is, the fourth speed, and the second planetary gear mechanism 4 and The output torque of the engine 1 is directly output only through the third gear pair 19, that is, without the need for hydraulic pressure to generate pressure oil flow and reaction torque between the pump motors 12 and 13. This is a state of transmission to the shaft 16.

  That is, the direct connection stage in the transmission TM is driven at the third speed by moving the sleeve 23S of the first sync 23 to the right in FIG. 1 from the state where the fourth speed, which is the highest speed stage, is set as described above. By engaging the gear 19A with the second intermediate shaft 10 and further moving the sleeve 25S of the R synchro 25 to the right in FIG. 1 to connect the sun gear 4S of the second planetary gear mechanism 4 and the carrier 4C. Is set. By connecting the sun gear 4S of the second planetary gear mechanism 4 and the carrier 4C in this way, the entire second planetary gear mechanism 4 is substantially integrated, that is, the second planetary gear mechanism 4 is in a so-called direct connection state. As a result, a power transmission path from the engine 1 to the output shaft 16 via the second planetary gear mechanism 4 and the third speed gear pair 19 is formed as indicated by a thick arrow in FIG.

  When the first sync 23 and the R sync 25 are operated to set the direct coupling stage as described above, the sleeve 24S of the second sync 24 is set to the center position and the second sync 24 is turned off. Thus, the second synchro 24 provided in the power transmission system on the first planetary gear mechanism 3 side is replaced with any transmission gear mechanism provided in the power transmission system on the first planetary gear mechanism 3 side, that is, The power transmission system on the first planetary gear mechanism 3 side and the first pump motor 12 connected thereto are set in a neutral state in which neither the second speed gear pair 18 nor the fourth speed gear pair 17 is engaged. The drag loss at can be reduced.

  In addition, when the first sync 23 and the R sync 25 are operated to set the direct coupling stage as described above, the relief valves 38 and 39 in the closed circuit CC are controlled to the open state (OFF state) and closed. By forcibly discharging the hydraulic pressure in the circuit CC, the hydraulic pressure is not applied to the pump motors 12 and 13, and the pump motors 12 and 13 can be brought into a free state in which they can idle ( ("FREE" is shown in FIG. 2). By doing so, hydraulic pressure is applied to the power transmission path from the engine 1 through the second planetary gear mechanism 4 and the third speed gear pair 19 to the output shaft 16 and any one of the pump motors 12 and 13. It is possible to avoid interference with a normal power transmission path when the reaction torque is generated.

Here, as described above, the gear ratio of the fourth-speed gear pair 17 (the number of teeth of the fourth-speed driven gear 17B) that is in a state where power can be transmitted to the output shaft 16 when setting the fourth speed. Is divided by the number of teeth of the fourth speed drive gear 17A), κ ₁ , when setting the third speed, the power transmission to the output shaft 16 is made possible, and when setting the direct coupling stage Also, the gear ratio of the third-speed gear pair 19 in which power can be transmitted to the output shaft 16 (value obtained by dividing the number of teeth of the third-speed driven gear 19B by the number of teeth of the third-speed drive gear 19A). Is κ ₂ , and the gear ratio between the sun gear 4S and the ring gear 4R of the second planetary gear mechanism 4 (value obtained by dividing the number of teeth of the sun gear 4S by the number of teeth of the ring gear 4R) is theoretically The fourth speed gear pair 17 and the third speed gear pair 19 are configured to satisfy the expression (1).
κ ₁ × κ ₂ = {1 / (1 + ρ)} (1)
Each of the planetary gear mechanisms 3 in FIG. 4 is configured by setting the respective transmission gear ratios κ ₁ and κ ₂ so as to satisfy the expression (1) and configuring the fourth speed gear pair 17 and the third speed gear pair 19, respectively. , 4, when the upshift is performed from the speed ratio between the third speed or the third speed and the fourth speed to the fixed speed ratio of the fourth speed, the speed ratio of the transmission TM is Simultaneously with the fourth gear ratio, the rotation of the sun gear 4S of the second planetary gear mechanism 4 and the rotation of the carrier 4C are synchronized.

However, in actuality, when the fixed gear ratio is set in a state where the transmission TM is loaded, the collinear diagram of FIG. 5 is caused by the influence of inevitable hydraulic leakage in the closed circuit CC. As indicated by ΔN, the rotational speed of the motor shaft 11, that is, the sun gear 4S of the second planetary gear mechanism 4 slightly decreases. Therefore, in consideration of such a phenomenon that the rotational speed of the sun gear 4S decreases, the fourth speed gear pair 17 and the third speed gear pair 19 are actually configured to satisfy the following expression (2). The
κ ₁ × κ ₂ ≦ {1 / (1 + ρ)} (2)
That is, the transmission gear ratios κ ₁ and κ ₂ are set so as to satisfy the equation (2) in consideration of a decrease in the rotational speed of the sun gear 4S due to hydraulic leakage in the closed circuit CC, and the fourth speed gear pair 17 and By configuring each of the third speed gear pairs 19, in actuality, when the upshift is performed from the third speed or the speed ratio between the third speed and the fourth speed to the fourth speed fixed speed ratio, the transmission The rotation of the sun gear 4S of the second planetary gear mechanism 4 and the rotation of the carrier 4C can be synchronized at the same time when the transmission ratio of TM becomes the fixed transmission ratio of the fourth speed.

For each of the gear ratios κ ₁ and κ ₂ that actually satisfy the above equation (2), for example, theoretically or designally estimates the leakage of hydraulic pressure in the closed circuit CC at the maximum load, or experimentally maximizes it. The hydraulic pressure leakage in the closed circuit CC at the time of load is measured, and the gear ratios κ ₁ and κ ₂ satisfying the above expression (2) are appropriately determined based on the estimated value or the measured value of the hydraulic leakage. Can do.

  As described above, the third speed gear pair 19 of the transmission TM is provided in the power transmission system on the side opposite to the fourth speed gear pair 17, and the sun gear of the second planetary gear mechanism 4 is provided by the R synchro 25. A transmission stage transmission mechanism that is capable of transmitting power to the output shaft 16 when the 4S and the carrier 4C are connected, and corresponds to the middle- and high-speed transmission mechanism in the present invention.

  Further, the reverse gear will be described. When the reverse position is selected by the shift device, the sleeve 22S of the S synchro 22 is moved to the left side of FIG. 1, and the sleeve 25S of the R synchro 25 is moved to the right side of FIG. The other syncs 23 and 24 are set to the OFF state. Therefore, when the second intermediate shaft 10 and the motor shaft 11 are connected by the R synchro 25, the sun gear 4S of the second planetary gear mechanism 4 and the carrier 4C are connected, and the entire second planetary gear mechanism 4 is substantially the same. Integrated. The start drive gear 21 </ b> A is connected to the motor shaft 9, that is, the rotor of the first pump motor 12.

  Therefore, the motive power transmitted from the engine 1 to the second planetary gear mechanism 4 is transmitted to the second pump motor 13 as it is, and this is driven, and hydraulic pressure is generated by the second pump motor 13. Since the first sync 23 is in the OFF state, power is not transmitted from the second planetary gear mechanism 4 or the second intermediate shaft 10 to the output shaft 16. On the other hand, the extrusion volume of the first pump motor 12 is controlled to a volume larger than zero, for example, the maximum volume. As a result, the first pump motor 12 functions as a motor by the hydraulic pressure supplied from the second pump motor 13 and outputs torque to the motor shaft 9. In that case, since the hydraulic pressure is supplied to the first pump motor 12 from the discharge port 12D, the first pump motor 12 rotates in the reverse direction. Then, the torque is transmitted to the output shaft 16 via the starting gear pair 21, so that a reverse state is established. That is, the reverse gear is set.

  As described above, the transmission TM targeted by the present invention is configured to be able to set four forward speeds and one reverse speed. At the fourth speed, which is the highest speed stage of forward movement of the transmission TM, as described above, the extrusion volume of the second pump motor 13 is set to “0”, and the rotation of the first pump motor 12 is locked. Thus, the rotation of the sun gear 3S of one of the first planetary gear mechanisms 3 provided on the first pump motor 12 side is fixed. As a result, the output torque of the engine 1 is transmitted to the output shaft 16 via the first planetary gear mechanism 3 and the fourth speed gear pair 17. Therefore, in the fourth speed, which is the highest speed stage and the fixed speed stage, so-called mechanical power transmission is performed without converting the power into a hydraulic flow, so the power transmission efficiency of the transmission TM is relatively low. Become good. In this state, the output torque of the engine 1 is directly transmitted to the output shaft 16 side without obtaining the reaction torque from the first pump motor 12, that is, the output torque of the engine 1 is transmitted to the output shaft 16 in a so-called direct connection state. If it is possible, the power transmission efficiency at the highest speed of the transmission TM can be further improved.

  Therefore, the control device according to the present invention executes the shift control to the highest speed, that is, the fourth speed in the transmission TM shown in FIG. 1 as shown in FIG. In this state, a so-called direct coupling stage is formed so that the power transmission efficiency at the highest speed stage can be improved.

  The control routine shown in FIG. 6 is repeatedly executed at predetermined short time intervals by the electronic control unit 43 described above. First, the travel state such as the accelerator opening θ, the engine speed Ne, and the vehicle speed V is shown. (Step S1), a target gear ratio is calculated based on the data, and a command for upshifting to the highest speed (specifically, upshifting to the fourth speed) is output as the calculation result. (Step S2).

  Subsequently, the rotation of the second pump motor 13, specifically, the rotation speed Npm2 of the motor shaft 11, that is, the sun gear 4S of the second planetary gear mechanism 4, and the rotation speed Nc2 of the carrier 4C of the second planetary gear mechanism 4 are read. Then, it is determined whether or not the rotation speed Npm2 of the second pump motor 13 and the rotation speed Nc2 of the carrier 4C are synchronized or almost synchronized (step S4). For example, the determination as to whether or not the synchronization has occurred is made by setting the absolute value of the deviation between the rotational speed Npm2 of the second pump motor 13 and the rotational speed Nc2 of the carrier 4C to “0” (zero) set as the threshold value. When the value falls below a close predetermined value (positive number), it can be determined that the rotation speed Npm2 of the second pump motor 13 and the rotation speed Nc2 of the carrier 4C are synchronized or substantially synchronized.

  If the determination is negative in this step S4 because the rotational speed Npm2 of the second pump motor 13 and the rotational speed Nc2 of the carrier 4C are not synchronized or almost synchronized with each other, the process returns to the above step S3. The above control is repeated. That is, the control in step S3 and step S4 is repeatedly executed until the rotation speed Npm2 of the second pump motor 13 and the rotation speed Nc2 of the carrier 4C are synchronized or substantially synchronized.

  If the determination is affirmative in step S4 because the rotational speed Npm2 of the second pump motor 13 and the rotational speed Nc2 of the carrier 4C are synchronized or almost synchronized, the process proceeds to step S5, and the R synchro 25 The sleeve 25S is moved to the right side in FIG. 1 to connect the sun gear 4S of the second planetary gear mechanism 4 and the carrier 4C. That is, a power transmission path from the engine 1 to the output shaft 16 via the second planetary gear mechanism 4 and the third speed gear pair 19 is brought into a directly connected state in which the rotating elements of the second planetary gear mechanism 4 rotate integrally. A so-called direct connection stage in which is formed is set.

At this time, as described above, when the transmission TM is upshifted to the fourth speed, the rotational speed Npm2 of the second pump motor 13 and the carrier at the same time when the speed ratio becomes the fixed speed ratio of the fourth speed. since 4C and rotation number Nc2 of the gear ratio kappa ₂ gear ratio kappa ₁ and the third gear pair 19 of the fourth gear pair 17 so as to be synchronized or nearly synchronized is set, as described above Thus, the synchronization between the rotational speed Npm2 of the second pump motor 13 and the rotational speed Nc2 of the carrier 4C is determined, and the state where the sun gear 4S of the second planetary gear mechanism 4 and the carrier 4C are connected, that is, the direct coupling stage is set. In this state, the transmission ratio of the transmission TM is equal to or substantially the same as the fixed transmission ratio of the fourth speed, which is the highest speed stage.

  In parallel with or following the operation of the sleeve 25S of the R synchro 25 in order to set the direct coupling stage as described above, the relief valves 38 and 39 in the closed circuit CC are in the open state (OFF state). ), The hydraulic pressure in the closed circuit CC is discharged (step S6). In this way, when setting the direct coupling stage, the relief valves 38 and 39 are opened to forcibly discharge the hydraulic pressure in the closed circuit CC, so that the hydraulic pressure does not act on the pump motors 12 and 13. That is, the pump motors 12 and 13 can be brought into a free state in which they can idle. Therefore, when a direct coupling stage is set, a power transmission path from the engine 1 to the output shaft 16 via the second planetary gear mechanism 4 and the third speed gear pair 19 and any one of the pump motors 12 and 13 It is possible to avoid interference with the normal power transmission path when the reaction force torque is generated by applying hydraulic pressure.

  At the same time, the sleeve 24S of the second sync 24 is moved to the center position, and the second sync 24 is turned off, that is, in a neutral state (step S7). In this way, when setting the direct coupling stage, the second synchro 24 is set to the neutral state, so that any transmission stage transmission mechanism arranged on the first planetary gear mechanism 3 side, that is, the fourth speed gear pair 17 is arranged. Both of the second speed gear pair 18 and the second speed gear pair 18 are in a state in which power transmission is interrupted to the engine 1, the first planetary gear mechanism 3, and the output shaft 16. Therefore, power transmission between the engine 1 and the first pump motor 12 can be interrupted in a state where the direct coupling stage is set, and generation of loss due to dragging the first pump motor 12 in that state is avoided. Can do.

  When the direct gear is set at the speed ratio of the highest speed as described above, the latest data indicating the running state such as the accelerator opening θ, the engine speed Ne, and the vehicle speed V is read again (step S8). Based on this, the target gear ratio is calculated, and as a result of the calculation, it is determined whether or not it is necessary to downshift from the direct gear to the fourth gear or lower (step S9). In other words, it is determined whether or not a command for downshifting to the fourth gear or lower is output.

  A negative determination was made in this step S9 because it is not necessary to downshift to a gear position below the fourth speed yet, or a downshift command to a gear stage below the fourth speed has not yet been output. In that case, the process returns to step S8 and the previous control is repeated. That is, the control in steps S8 and S9 is repeatedly executed until a downshift to a gear position below the fourth speed becomes necessary or a downshift command to a gear stage below the fourth speed is output. The

  If the determination in step S9 is affirmative due to the necessity of downshifting to the fourth speed or lower, or the output of a downshift command to the fourth or lower speed. In step S10, the sleeve 24S of the second sync 24 is moved to the right side in FIG. 1 so that the fourth speed gear pair 19 can transmit power to the output shaft 16.

  Subsequently, the relief valves 38 and 39 in the closed circuit CC that have been controlled to the open state (OFF state) are returned to the normal control state (ON state), respectively, and the hydraulic pressure in the closed circuit CC is restored. The hydraulic pressure is returned to the pump motors 12 and 113 (step S11). At the same time or subsequently, the sleeve 25S of the R sync 25 is moved to the center position, and the R sync 25 is turned off, that is, neutral (step S12).

  As described above, the fourth speed gear pair 19 is brought into a state in which power can be transmitted to the output shaft 16, the hydraulic pressure in the closed circuit CC is restored, and the R synchro 25 is made neutral, so that Thus, it becomes possible to set the fixed gear ratio of the speed, and therefore downshifting to the gear stage of the fourth speed or less is started (step S13). Thereafter, this routine is once terminated.

  As described above, according to the control device for the variable displacement pump motor type transmission according to the present invention, the fourth speed gear pair 17 is installed when the transmission TM is upshifted to the highest speed, that is, the fourth speed. The rotational speed Npm2 of the sun gear 4S of the second planetary gear mechanism 4 on the side not yet connected is compared with the rotational speed Nc2 of the carrier 4C. When the rotation of the 4S and the carrier 4C is synchronized or almost synchronized, the R synchro 25 that also serves as the direct connection stage switching mechanism in the present invention is controlled, and the sun gear 4S and the carrier 4C of the second planetary gear mechanism 4 are They are connected so as to rotate together. As a result, all the rotating elements of the second planetary gear mechanism 4 are rotated integrally. That is, the input element and the output element of the second planetary gear mechanism 4 rotate together, and the engine 1 and the output shaft 16 are directly connected. Therefore, when setting the highest speed stage of the transmission TM, the engine 1 and the output shaft 16 are directly connected together with the highest speed stage set by the gear pair 17 for the fourth speed, which is the fastest fixed gear ratio. The so-called direct coupling stage can be formed, and the output torque of the engine 1 can be directly transmitted to the output output shaft 16.

  Therefore, the transmission of power from the engine 1 to the output shaft 16 in the state where the highest speed stage is set causes the flow of pressure oil between the pump motors 12 and 13 and the reaction torque generated by the pump motors 12 and 13. Can be performed only through the second planetary gear mechanism 4 and the third speed gear pair 19 without requiring the hydraulic pressure for the pressure, and the hydraulic pressure for generating the flow of the pressure oil and generating the reaction torque is required. By not, loss such as hydraulic leakage in the closed circuit CC can be reduced, and as a result, power transmission efficiency at the highest speed stage of the transmission TM can be improved.

  Here, the relationship between the above-described specific example and the present invention will be briefly described. The functional means for executing steps S4 to S7 in the flowchart of FIG. 6 corresponds to the direct connection step forming means in the present invention. Of these, the functional means for executing step S6 corresponds to the means for controlling the relief valve in the open state in the invention of claim 2, and the functional means for executing step S7 is one of the differences in the invention of claim 3. This corresponds to a means for controlling the switching mechanism provided on the moving mechanism side to a neutral state.

  Note that the present invention is not limited to the above-described specific example, and the target transmission TM may have a configuration other than that shown in FIG. 1. In short, transmission is performed by at least two power transmission systems. The torque can be changed according to the extrusion volume of the hydraulic pump motor, so the torque is transmitted via only one power transmission system to set the gear ratio, and the torque is transmitted via both power transmission systems. Any transmission TM may be used as long as the transmission ratio can be set by transmission. In the case where the fixed gear ratio can be set, the fixed gear ratio may be greater than the fourth speed, or vice versa.

  Further, in FIG. 1 described above, importance is placed on the power transmission efficiency when the direct coupling stage which is a feature of the present invention is set, and the engine 1 is directly connected to the power transmission system on the first planetary gear mechanism 3 and the first pump motor 12 side. The connected configuration, that is, the configuration in which the ring gear 3R of the first planetary gear mechanism 3 and the engine 1 are directly coupled via the input member 2 and the counter drive gear 5, is illustrated. As shown in FIG. Focusing on the power transmission efficiency when setting the fourth speed as the ratio, the configuration in which the engine 1 is directly connected to the power transmission system on the second planetary gear mechanism 4 and the second pump motor 13 side, that is, the second planetary gear mechanism. 4 ring gear 4R and engine 1 are replaced with input member 2 and counter drive gear 5 (the arrangement of counter drive gear 5 and counter driven gear 7 in FIG. 1 is switched). It may be configured to be directly connected via a.

  That is, the power transmission efficiency at each fixed speed ratio (herein, the fourth speed and the third speed) of the transmission TM is such that the engine 1 is connected to the first planetary gear mechanism 3 and the first pump motor 12 side, i. When directly connected to the power transmission system on the (speed) side, the number of meshes between the input member 2 and the output shaft 16 is small, and therefore, as shown by the line L1 (solid line) in FIG. The third speed has better power transmission efficiency. On the other hand, when the engine 1 is directly connected to the second planetary gear mechanism 4 and the power transmission system on the second pump motor 13 side, that is, the highest speed stage (fourth speed) side, the line L2 in FIG. As indicated by (broken line), power transmission efficiency is better at the fourth speed than at the third speed. Therefore, in the configuration of the transmission TM that is the subject of the present invention in which the direct coupling stage is formed via the third speed gear pair 19 as described above, the third speed is indicated by a point P1 (◯) in FIG. When the engine 1 is directly connected to the power transmission system on the side, the power transmission efficiency in the state where the direct connection stage is set is better than when the engine 1 is directly connected to the power transmission system on the fourth speed side. Become.

  On the other hand, as shown by a point P2 (●) in FIG. 8, when the engine 1 is directly connected to the power transmission system on the fourth speed side, the engine 1 is directly connected to the power transmission system on the third speed side. The power transmission efficiency in the state where the direct coupling stage is set is slightly lower than in the case, but the power transmission efficiency is better at the fourth speed than at the third speed as described above, so that the fixed gear ratio is obtained. When emphasizing the power transmission efficiency when the fourth speed is set, it is also effective to directly connect the engine 1 to the power transmission system on the fourth speed side.

  In the present invention, a mechanism such as a belt or a chain may be used instead of the gear pair. In the case of using a gear mechanism having a differential action in the present invention, for example, a double pinion type planetary gear mechanism can be used instead of the single pinion type planetary gear mechanism, or a further configuration of the differential gear mechanism is used. You can also

It is a skeleton figure which shows typically an example of the variable capacity type pump motor type transmission made into object by this invention. FIG. 2 is a chart collectively showing an operation state of the transmission shown in FIG. 1. FIG. It is a figure which shows typically the flow of motive power in the state which set the direct connection stage with the transmission shown in FIG. It is a collinear diagram about the 1st planetary gear mechanism and the 2nd planetary gear mechanism in the case of driving from the 3rd speed to the 4th speed. FIG. 5 is a collinear diagram for the first planetary gear mechanism and the second planetary gear mechanism when operating at the fourth speed, and illustrates a state in which the rotation speed decreases when there is a load with respect to no load (theoretical value). FIG. It is a flowchart for demonstrating an example of the control performed with the control apparatus which concerns on this invention. It is a skeleton figure which shows typically the other example of the variable capacity type pump motor type transmission made into object by this invention. FIG. 8 is a schematic diagram for explaining a difference in power transmission efficiency between the configuration of the transmission shown in FIG. 1 and the configuration of the transmission shown in FIG. 7.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Power source (engine, Eng), 2 ... Input member, 3 ... Differential mechanism (1st planetary gear mechanism), 4 ... Differential mechanism (2nd planetary gear mechanism), 3R, 4R ... Input element (ring gear) 3S, 4S ... reaction force element (sun gear), 3C, 4C ... output element (carrier), 12 ... variable displacement pump motor (first pump motor, PM1), 13 ... variable displacement pump motor (second pump motor) , PM2), 14, 15 ... oil passage, 16 ... output member (output shaft), 17, ... 20 ... transmission mechanism for gear stage (gear pair), 17 ... transmission mechanism for maximum speed stage (gear pair for fourth speed) ), 19... Medium- and high-speed stage transmission mechanism (gear pair for third speed) 22 to 25... Switching mechanism (synchronizer) 25. Direct coupling stage switching mechanism (R synchro) 38 and 39. Valve), 40 ... Electronic control unit (E CU), CC ... closed circuit, TM ... variable displacement pump motor type transmission.

Claims (6)

Two differential mechanisms connected in parallel to the power source and having input elements to which the output torque of the power source is input, and reaction force torque or A closed circuit formed by two variable displacement pump motors that selectively apply drive torque, and two oil passages that connect the discharge ports and the suction ports of the variable displacement pump motors; A plurality of transmission gear mechanisms that are provided between an output element of each differential mechanism and an output member and that are selectively controlled to transmit power by controlling a switching mechanism and that have different gear ratios; In a control device for a variable displacement pump motor type transmission comprising:
A reaction force element of the other differential mechanism on the side opposite to the one of the differential mechanisms on the side on which the transmission mechanism for the highest speed stage having the smallest speed ratio is provided among the plurality of transmission gears for the shift speeds; A direct connection stage switching mechanism for selectively connecting the output elements;
The speed of the reaction force element of the other differential mechanism and the number of revolutions of the output element are changed so that the transmission mechanism for the highest speed stage can transmit power to the output member and the speed is changed to the highest speed And a direct connection stage forming means for controlling the direct connection stage switching mechanism to connect the reaction force element and the output element of the other differential mechanism when they are synchronized or substantially synchronized with each other. Control device for variable displacement pump motor type transmission. A pressure regulating valve that discharges the hydraulic pressure in the closed circuit by setting a relief pressure that defines an upper limit of the hydraulic pressure in the closed circuit and being controlled in an open state;
2. The direct connection stage forming means includes means for controlling the pressure regulating valve to an open state when the reaction force element and the output element of the other differential mechanism are connected to each other. Control device for variable displacement pump motor type transmission.   When the reaction force element and the output element of the other differential mechanism are connected to each other, the direct coupling stage forming means uses any one of the shift stage transmissions as the switching mechanism provided on the one differential mechanism side. 3. The control apparatus for a variable displacement pump motor type transmission according to claim 1, further comprising means for controlling the neutral state so as not to engage with the mechanism. At least the other differential mechanism is constituted by a planetary gear device having a ring gear, a sun gear, and a carrier as the input element, the reaction force element, and the output element, respectively.
Of the gear ratio ρ between the ring gear and the sun gear, the gear ratio κ _{1 of the} transmission mechanism for the highest speed stage and the transmission mechanism for the transmission stage provided on the opposite side of the transmission mechanism for the highest speed stage, the direct connection A gear ratio κ _{2 of the} medium-to-high speed stage transmission mechanism that is configured to transmit power when the reaction force element and the output element of the other differential mechanism are coupled by the stage forming means;
κ ₁ × κ ₂ ≦ {1 / (1 + ρ)}
The other differential mechanism, the transmission mechanism for the highest speed stage, and the transmission mechanism for the medium to high speed stage are configured so as to satisfy the relationship. Control device for variable displacement pump motor type transmission.   The variable member according to any one of claims 1 to 4, wherein an input member to which an output torque of the power source is directly transmitted and an input element of the other differential mechanism are coupled so as to be integrally rotatable. Control device for displacement pump motor type transmission.   5. The variable according to claim 1, wherein an input member to which an output torque of the power source is directly transmitted and an input element of the one differential mechanism are coupled so as to be integrally rotatable. Control device for displacement pump motor type transmission.

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