JP5822909B2 - Hydraulic system for continuously variable transmission - Google Patents

Description

  The present invention is a hydraulic system used in a conical disk-type winding transmission, and the conical disk-type winding transmission includes a first conical disk set and a second conical disk set. A moment sensor is correspondingly arranged in the first conical disc set, and the pressing and / or adjustment of the second conical disc set is provided by a hydraulic pressure source under the presence of a plurality of valves. The present invention relates to a hydraulic system used in a conical disk-type wound transmission that is controlled by a pressure.

  The hydraulic system mentioned at the beginning is known from German Offenlegungsschrift 4234294 and WO 2007/110026. The pressing and / or adjustment of the conical disc set can be realized in the form of a single piston (single piston) or a double piston (double piston). The use of a single piston is also called the single piston principle. Similar to this, the use of a double piston is also called the double piston principle.

  The object of the present invention is to improve the hydraulic system according to the superordinate concept part of claim 1 and to operate a single piston provided in a second conical disc set according to the double piston principle. To provide a hydraulic system that can be used in combination with a moment sensor provided in a disk set.

  In order to solve this problem, according to the hydraulic system of the present invention, the double-piston principle in which the pressing / adjusting pressure chamber of the second conical disk set working according to the single-piston principle and the moment sensor are arranged correspondingly. An adjustable hydraulic resistance is connected between the pressing pressure chamber of the first conical disc set working according to

  According to an advantageous embodiment of the hydraulic system according to the invention, the adjustable hydraulic resistance is formed as a differential pressure valve.

  According to an advantageous aspect of the hydraulic system according to the invention, a clutch cooling means is placed after the moment sensor of the first conical disc set.

  According to an advantageous embodiment of the hydraulic system according to the invention, a volumetric flow control valve is placed after the hydraulic pressure source.

  According to an advantageous embodiment of the hydraulic system according to the invention, a counterbalance valve is connected between the hydraulic pressure source or the volume flow regulating valve and the adjustable hydraulic resistance.

  According to an advantageous aspect of the hydraulic system according to the present invention, a guide amount adjusting valve is connected between the hydraulic pressure source or the volume flow rate adjusting valve and the counter balance valve.

  According to an advantageous embodiment of the hydraulic system according to the invention, a minimum pressure valve is connected between the suction system of the hydraulic pressure source and the volume flow regulating valve.

  According to an advantageous embodiment of the hydraulic system according to the invention, a part of the hydraulic medium provided by the hydraulic pressure source is branched between the volume flow regulating valve and the minimum pressure valve. .

  According to an advantageous embodiment of the hydraulic system according to the invention, a plurality of pressure-reducing valves are placed after the hydraulic pressure source.

  According to an advantageous embodiment of the hydraulic system according to the invention, one of the pressure reducing valves is arranged corresponding to the regulating pressure chamber of the first conical disc set, and one of the pressure reducing valves is One pressure reducing valve is arranged corresponding to the clutch and / or one pressure reducing valve among the pressure reducing valves is arranged corresponding to the guide amount adjusting valve.

  The above-described problem is a hydraulic system used in a conical disk-type winding transmission, in which the conical disk-type winding transmission includes a first conical disk set and a second conical disk set. A moment sensor is correspondingly arranged on the first conical disc set, and pressing and / or adjustment of the second conical disc set is provided by a hydraulic pressure source under the intervention of a plurality of valves A hydraulic system used in a conical disk-type wound transmission, which is adapted to be controlled by a pressure applied to a second conical disk set pressing / adjusting pressure chamber working according to the single piston principle; Pressing pressure of the first conical disc set working according to the double piston principle with correspondingly arranged moment sensors Between the adjustable hydraulic resistance is resolved by being connected. This arrangement has the advantage that a pressure higher than the pressure set by the moment sensor of the first conical disc set can be generated in the pressing / adjusting pressure chamber of the second conical disc set. ing. The moment sensor is advantageously designed as a pressure limiting valve. The hydraulic system according to the invention advantageously has the following distinct functions: pressing / adjustment of the second conical disc set, pressing of the first conical disc set and of the first conical disc set. Regulation: fulfills. In addition, the hydraulic system according to the invention additionally performs at least one, preferably more or all of the following functions: clutch cooling, clutch operation, oiling, lubrication and disk set cooling. Can do. In the single piston principle, the disc set has a kind of pressure cylinder with a single piston. In the double piston principle, the cylinder surface of the disc set is divided and combined with the double piston.

  One advantageous aspect of the hydraulic system is characterized in that the adjustable hydraulic resistance is formed as a differential pressure valve. The differential pressure valve is advantageously hydraulically controlled by the pressure before and after the differential pressure valve.

  Another advantageous aspect of the hydraulic system is characterized by the fact that a clutch cooling means is located after the moment sensor of the first conical disc set. This clutch cooling means is preferably placed directly after the moment sensor. The hydraulic medium reaches the moment sensor from the hydraulic pressure source via the hydraulic resistance. This hydraulic medium is subsequently used for clutch cooling.

  Another advantageous embodiment of the hydraulic system is characterized by the fact that a volumetric flow regulating valve is placed after the hydraulic pressure source. This volume flow regulating valve is preferably formed as a proportional or servo valve with a two-port two-position directional control valve structure. The volume flow rate adjusting valve can change the flow rate of the hydraulic medium flowing to the clutch cooling means through the moment sensor. The variability in volumetric flow to the moment sensor allows, in part, a minimal supply to the moment sensor with minimal clutch cooling. In addition, there is the possibility of providing a high volume flow for maximum clutch cooling.

  Another advantageous aspect of the hydraulic system is characterized by the fact that a counterbalance valve is connected between the hydraulic pressure source or volume flow regulating valve and the adjustable hydraulic resistance. A hydraulic medium is supplied from a hydraulic pressure source. This hydraulic medium reaches the moment sensor via the counterbalance valve and the hydraulic resistance. A counter balance valve can provide the desired system pressure. The counterbalance valve may advantageously be preceded by a hydraulic resistance, for example in the form of a first throttle.

  Another advantageous aspect of the hydraulic system is characterized by a guide amount regulating valve connected between the hydraulic pressure source or volume flow regulating valve and the counterbalance valve. The guide amount adjusting valve is preferably formed as a proportional valve or servo valve having a two-port two-position direction control valve structure. The guide amount of the volume flow rate adjusting valve can be changed by the guide amount adjusting valve. The guide adjustment valve can advantageously be provided with another hydraulic resistance, for example in the form of a second throttle. The second diaphragm advantageously has a larger diaphragm cross section than the first diaphragm. Therefore, under the same conditions, more hydraulic medium than the first throttle reaches the counter balance valve via the second throttle and the opened guide amount adjusting valve.

  Another advantageous aspect of the hydraulic system is characterized by a minimum pressure valve connected between the suction system of the hydraulic pressure source and the volume flow regulating valve. The hydraulic pressure source is preferably formed as a hydraulic pump. The hydraulic pump draws hydraulic medium from the tank and pumps it through a plurality of valves to a plurality of consumers of the hydraulic system. The minimum pressure valve maintains a desired minimum pressure between the volume flow control valve and the minimum pressure valve.

  Another advantageous embodiment of the hydraulic system is characterized in that a part of the hydraulic medium provided by the hydraulic pressure source is branched between the volume flow regulating valve and the minimum pressure valve. . The branched hydraulic medium is used, for example, for oiling, lubrication and / or disk set cooling.

  Another advantageous embodiment of the hydraulic system is characterized by the fact that a plurality of pressure reducing valves are placed behind the hydraulic pressure source. These pressure-reducing valves are preferably formed as proportional valves or servo valves with a three-port two-position directional control valve structure and are hydraulically operated. The pressure reducing valve is preferably connected directly to the discharge side of a hydraulic pressure source formed as a hydraulic pump, optionally with a filter.

  Another advantageous aspect of the hydraulic system is that one of the pressure reducing valves (third pressure reducing valve) is arranged corresponding to the regulating pressure chamber of the first conical disc set, Another pressure reducing valve (second pressure reducing valve) of the valves is arranged corresponding to the clutch and / or yet another pressure reducing valve (first pressure reducing valve) of the pressure reducing valves is arranged. It is characterized by being arranged corresponding to the guide amount adjusting valve. The pressure in the adjusting pressure chamber of the first conical disk set is adjusted by the first reducing valve (third reducing valve). This pressure reducing valve thus serves for the support or adjustment of the variator arranged corresponding to the first conical disc set. This support or adjustment requires an additional axial force on the first conical disc set. The pressure reducing valve (second pressure reducing valve) described next adjusts the clutch pressure of the clutch, preferably the starting clutch, which is disposed in front of the conical disk-type wound transmission. The pressure reducing valve (first pressure reducing valve) described last adjusts the pressure for controlling the guide amount adjusting valve that changes the guide amount of the volume flow rate adjusting valve.

  Further advantages, features and details of the present invention will be apparent from the following description in which one embodiment has been described in detail with reference to the drawings.

1 is a partially simplified illustration of a hydraulic system according to the present invention in the form of a hydraulic circuit diagram.

  In FIG. 1, a hydraulic system 1 with a hydraulic pressure source 2 is shown partially simplified in the form of a hydraulic circuit diagram. The hydraulic pressure source 2 is formed as a hydraulic pump 4. The hydraulic pump 4 sucks a hydraulic medium such as hydraulic (working) oil from a tank 6 through a filter 5. The tank side of the pump 4 is also called a suction side or a suction system. Analogously to this, the side of the hydraulic pump 4 opposite to the filter 5 and the tank 6 is called the discharge side.

  The hydraulic system 1 according to the present invention serves to hydraulically control various functions of a conical disk-type wound transmission that is also called a CVT transmission (Continuously Variable Transmission). Such a conical disc-type wound transmission is described, for example, in German Offenlegungsschrift 4234294 or WO 2007/110026, and includes a first conical disc set and a second conical disc set. A conical disc set.

  The first conical disc set of the conical disc type wound transmission used in the present embodiment operates according to the double piston principle, whereas the second conical disc set follows the single piston principle. Work. Accordingly, one common pressing / adjusting pressure chamber 8 is correspondingly arranged, that is, assigned to the second conical disk set. One pressing pressure chamber 9 and one separate adjustment pressure chamber 14 are arranged corresponding to the first conical disc set having the moment sensor 10 also called a torque sensor.

  When viewed in the direction of force transmission, a clutch 12 is provided in front of the conical disk-type wound transmission. The clutch 12 is also called a starting clutch and has clutch cooling means 11. By means of the hydraulic system 1 according to the invention, the pressing / adjusting pressure chamber 8 of the second conical disc set, the pressing pressure chamber 9 of the first conical disc set, and the moment sensor of the first conical disc set 10, the clutch cooling means 11, the clutch 12, the regulating pressure chamber 8 of the first conical disk set, and at least one further consumer 15 can be hydraulically controlled. This further consumer 15 includes, for example, oil supply means, lubrication means and / or disk set cooling means.

  A connecting pipe 18 is connected to the discharge side of the pump 4. This connection pipe line 18 includes five branch points numbered 1 to 5 below from left to right in FIG. Therefore, the leftmost branch point in FIG. 1 is called the first branch point, and the rightmost branch point in FIG. 1 is called the fifth branch point. A branch point arranged between both branch points is called a second branch point, a third branch point, and a fourth branch point.

  A first branch point of the connecting pipe 18 is connected between the volume flow rate adjusting valve 20 and the counter balance valve 21. A first throttle and another branch point are connected in series between the first branch point and the counter balance valve 21. From this other branch point, the hydraulic pipe line extends to the guide amount adjusting valve 24. A second throttle is disposed between the third branch point of the connecting pipe 18 and the guide amount adjusting valve 24. A control line extends from the second branch point of the connecting line 18 to the volume flow rate adjusting valve 20. Another control line 23 extends from the volume flow rate adjusting valve 20 to a branch point ahead of the counter balance valve 21.

  Another filter 25 is disposed between the third branch point and the fourth branch point of the connection pipe line 18. A first pressure reducing valve 31 is connected to the fourth branch point of the connection pipe line 18. A second pressure reducing valve 32 is connected to the fifth branch point of the connection pipe line 18. In FIG. 1, a third pressure reducing valve 33 is connected to the right end of the connection pipe line 18.

  The third pressure reducing valve 33 is connected to the adjusting pressure chamber 14 of the first conical disk set via a hydraulic pipe line 34. The second pressure reducing valve 32 is connected to the clutch 12 via a pressure relief valve 35 and a hydraulic pipe line 38. The first pressure reducing valve 31 can be connected to the control pressure branch point 36. The control pressure branch point 36 is connected to the pressure relief valve 35, the first pressure reducing valve 31 itself, and the guide amount adjusting valve 24 through a plurality of control lines.

  A minimum pressure valve 40 is connected between the suction system in the pump 4 and the volume flow rate adjustment valve 20. Between the minimum pressure valve 40 and the volume flow rate adjustment valve 20, the hydraulic medium can be branched to the consumer 15 via the branch line 42. Furthermore, the consumer 15 is connected to the tank 6 indicated at different points in the hydraulic system 1 by corresponding symbols. In the branch line 42, another filter is connected in parallel with the check valve. Another throttle is connected between the parallel connection portion and the consumer 15.

  The pressing pressure chamber 9 of the first conical disc set is connected via a connecting line 44 to a torque sensor 10 which is preferably formed as a pressure limiting valve. A clutch cooling means 11 is directly placed on the torque sensor 10. According to the main embodiment of the present invention, the hydraulic resistance 45 is connected between the counterbalance valve 21 and the connection pipe line 44. The hydraulic resistance 45 is formed as a differential pressure valve that is hydraulically controlled by the pressure before and after the hydraulic resistance 45.

  The oil pumped by the pump 4 reaches the pressing pressure chamber 9 and the torque sensor 10 of the first conical disk set via the counter balance valve 21, the differential pressure valve 45, and the connection pipe 44. Oil is directly used for the clutch cooling means 11 behind the torque sensor 10 or moment sensor. From this clutch cooling means 11, the oil is returned to the tank 6.

  The hydraulic system 1 according to the present invention returns to the torque sensor 10 by returning a part of the oil pumped by the pump 4 in parallel to the suction system of the pump 4 via the volume flow rate adjusting valve 20 and the minimum pressure valve 40. Offers the possibility of changing the volumetric flow rate. In front of the minimum pressure valve 40, the oil branches to a consumer 15, for example a disk set cooling means and a lubricating means. The volume flow control valve 20 is formed as a servo valve or a proportional valve having two ports and two switching positions. A preload is applied to the volume flow regulating valve 20 by a spring at the closed position shown in FIG. 1 where the connection between the first branch point of the connecting pipe 18 and the minimum pressure valve 40 or the branch pipe 42 is cut off. It has been. When the preload force of the spring exceeds the pressure difference between the second branch point of the connecting pipe 18 and the control pipe 23, the volume flow rate adjusting valve 20 is opened.

  The system pressure of the hydraulic system 1 is first defined by the moment sensor 10. When higher system pressure is required for adjustment, the required system pressure increase can be achieved by the counterbalance valve 21 or the differential pressure valve 45.

  The guide amount adjusting valve 24 is formed as a servo valve or a proportional valve having two ports and two switching positions. A preload is applied to the guide amount adjusting valve 24 by a spring in the illustrated closed position. The control pressure of the guide amount adjusting valve 24 is adjusted by the first pressure reducing valve 31. Both the first pressure reducing valve 31 and the other pressure reducing valves 32 and 33 are formed as servo valves or proportional valves having three ports and two switching positions, and are hydraulically operated. The pressure reducing valves 31, 32, 33 are preloaded by springs at the illustrated switching positions.

  The guide pressure adjusting valve 24 is controlled by the first pressure reducing valve 31 via the control pressure branch point 36. Furthermore, the guide amount of the flow rate adjusting valve 20 is changed by the guide amount adjusting valve 24 via the second branch point of the connection pipe line 18 and the control pressure line 23, and consequently the volume flow rate to the moment sensor 10 is changed. Is controlled.

  This control of the volumetric flow rate to the moment sensor 10 can, in part, ensure a minimum supply amount coupled with minimal clutch cooling. Second, volumetric flow control can provide high volumetric flow for maximum clutch cooling. The pressure formed at the control pressure branch point 36 of the first pressure reducing valve 31 is also used to control the pressure relief valve 35.

  The second pressure reducing valve 32 adjusts the clutch pressure of the clutch 12. When an error occurs, the clutch pressure of the clutch 12 can be released to the tank 6 by the pressure relief valve 35 controlled via the control pressure branch point 36.

  The third pressure reducing valve 33 adjusts the pressure in the adjusting pressure chamber 14 of the first conical disk set, thereby supporting or adjusting the variator arranged corresponding to the first conical disk set. work. This support or adjustment requires an additional axial force on the first conical disc set. The pressure in the regulating pressure chamber 14 of the first conical disc set is also used as a control pressure for the counterbalance valve 21 via a separate control line 50, thereby possibly increasing the system pressure. .

  The pressure in the pressing / adjusting pressure chamber 8 of the second conical disk set formed as a single piston is first set by the moment sensor 10. In order to achieve support or adjustment that requires additional axial force on the second conical disc set, the pressure in the pressing and adjusting pressure chamber 8 must be increased beyond the moment sensor pressure. . This pressure increase is made possible by a differential pressure valve 45 arranged between the pressing / adjusting pressure chamber 8 of the second conical disc set and the pressing pressure chamber 9 or moment sensor 10 of the first conical disc set. Become. The differential pressure valve 45 can generate a pressure larger than the pressure set by the moment sensor 10 in the pressing / adjusting pressure chamber 8 of the second conical disk set.

DESCRIPTION OF SYMBOLS 1 Hydraulic system 2 Hydraulic pressure source 4 Hydraulic pump 5 Filter 6 Tank 8 Pressing / adjusting pressure chamber 9 Pressing pressure chamber 10 Moment sensor 11 Clutch cooling means 12 Clutch 14 Adjusting pressure chamber 15 Consumer 18 Connection pipe 20 Volume flow Adjustment valve 21 Counter balance valve 23 Control line 24 Guide amount adjustment valve 25 Filter 31 First pressure reducing valve 32 Second pressure reducing valve 33 Third pressure reducing valve 34 Hydraulic line 35 Pressure relief valve 36 Control pressure branch point 38 Hydraulic line 40 Minimum pressure valve 42 Branch line 44 Connection line 45 Hydraulic resistance 50 Control line

Claims (10)

A hydraulic system used in a conical disk-type wound transmission,
A conical disc-type winding transmission includes a first conical disc set and a second conical disc set;
A moment sensor (10) is arranged corresponding to the first conical disc set;
Conical disc winding, wherein the pressing and / or adjustment of the second conical disc set is controlled by the pressure provided by the hydraulic pressure source (2) under the intervention of a plurality of valves In the hydraulic system used for the transmission,
Pushing / adjusting pressure chamber (8) of the second conical disc set working according to the single piston principle and a moment sensor (10) correspondingly, pushing of the first conical disc set working according to the double piston principle An adjustable hydraulic resistance (45) is connected between the pressure chamber (9) and the first conical in the pressing / adjusting pressure chamber (8) of the second conical disc set. characterized Rukoto to generate a higher pressure than the pressure set by the moment sensor (10) in the form a disk set, hydraulic systems used in the conical disc-type wrapping transmission.   The hydraulic system according to claim 1, wherein the adjustable hydraulic resistance is formed as a differential pressure valve.   The hydraulic system according to claim 1 or 2, wherein the clutch cooling means (11) is placed after the moment sensor (10) of the first conical disc set.   The hydraulic system according to any one of claims 1 to 3, wherein a volumetric flow rate adjusting valve (20) is placed behind the hydraulic pressure source (2).   The hydraulic system according to claim 4, wherein a counterbalance valve (21) is connected between the hydraulic pressure source (2) or the volumetric flow control valve (20) and the adjustable hydraulic resistance (45). .   The hydraulic system according to claim 5, wherein a guide amount adjusting valve (24) is connected between the hydraulic pressure source (2) or the volume flow rate adjusting valve (20) and the counter balance valve (21).   The hydraulic system according to any one of claims 4 to 6, wherein a minimum pressure valve (40) is connected between the suction system of the hydraulic pressure source (2) and the volume flow rate regulating valve (20).   The part of the hydraulic medium provided by the hydraulic pressure source (2) is adapted to be branched between the volume flow regulating valve (20) and the minimum pressure valve (40). Hydraulic system.   The hydraulic system according to any one of claims 1 to 8, wherein a plurality of pressure reducing valves (31, 32, 33) are disposed behind the hydraulic pressure source (2).   One pressure reducing valve (33) of the pressure reducing valves is arranged corresponding to the control pressure chamber (14) of the first conical disk set, and one pressure reducing valve (32) of the pressure reducing valves is connected to the clutch. The hydraulic system according to claim 9, wherein the pressure reducing valve (31) is arranged corresponding to (12) and / or one pressure reducing valve (31) of the pressure reducing valves is arranged corresponding to the guide amount adjusting valve (24).

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