JP4391487B2 - Hydraulic control circuit for continuously variable transmission - Google Patents

Description

  The present invention relates to a hydraulic control circuit for a continuously variable transmission. More particularly, the present invention relates to a hydraulic control circuit that controls driving of a continuously variable transmission used in a power generation device driven by an engine such as an aircraft or a vehicle.

  2. Description of the Related Art Conventionally, a power generation device driven by an engine output of an aircraft is known as an aircraft power generation device. In this power generation apparatus, a transmission is provided between the engine and the power generation apparatus because the rotation speed of the power generation apparatus needs to be constant even if the engine output, that is, the engine rotation speed fluctuates.

  Attempts have been made to use a toroidal continuously variable transmission as this transmission. In this toroidal-type continuously variable transmission, a power roller is disposed so as to be tiltable between a pair of input disks and output disks formed on a toroidal curved surface, and the tilt angle of the power roller is controlled to control the transmission. The output rotational speed is constant, that is, the generator rotational speed is constant.

  However, since the control of the tilt angle is performed using a hydraulic control circuit, immediately after the engine is started, the fluidity of the control oil is not sufficient, so that there is a problem that rapid start-up cannot be performed. is there. This problem becomes a big problem in starting in a cold region.

  The present invention has been made in view of the problems of the prior art, and an object of the present invention is to provide a hydraulic control circuit for a continuously variable transmission that can quickly start the continuously variable transmission even in a cold region.

A hydraulic control circuit of a continuously variable transmission according to the present invention is a hydraulic control circuit that controls a hydraulic servo mechanism of a continuously variable transmission, and is disposed upstream of the hydraulic control circuit , and the servo of the hydraulic servo mechanism. In a hydraulic control circuit including a hydraulic pump that boosts oil supplied to the valve to a predetermined pressure, a return pipe that raises the temperature of the oil by returning a part of the oil boosted by the hydraulic pump to the hydraulic pump; and the temperature is increased oil and characterized in that it comprises further a warm-up tube to warm up the sprayed can attach to the servo valve to the servo valve of the hydraulic servo mechanism.

  In the hydraulic control circuit of the continuously variable transmission according to the present invention, it is preferable that the warm-up pipe includes a flow fuse valve.

  In the hydraulic control circuit of the continuously variable transmission according to the present invention, the hydraulic control circuit is preferably branched from the oil circulation system.

  According to the present invention, since the hydraulic control circuit includes the warm-up pipe for warming up the servo valve, the servo valve is warmed up quickly, and the continuously variable transmission can be quickly started even in a cold region. An excellent effect is obtained.

  Further, according to the preferred embodiment of the present invention including the flow fuse valve, an excellent effect that the hydraulic pump is protected at a low rotation speed of the hydraulic pump can be obtained.

  Furthermore, according to another preferred embodiment of the present invention in which the hydraulic control circuit is branched from the oil circulation system, the servo valve warm-up is accelerated and the continuously variable transmission can be started more quickly. can get.

  Hereinafter, although the present invention is explained based on an embodiment, referring to an accompanying drawing, the present invention is not limited only to this embodiment.

  An oil including a hydraulic control circuit (hereinafter simply referred to as a hydraulic control circuit) 10 of a toroidal type continuously variable transmission (hereinafter simply referred to as a continuously variable transmission) 1 having a tilt angle adjusting mechanism 2 according to an embodiment of the present invention. The system | strain 30 is shown in FIGS. In addition, this embodiment shall be applied to the aircraft power generation device. Further, since the continuously variable transmission 1 and the tilt angle adjusting mechanism 2 can be suitably used, a detailed description of their configurations is omitted.

  The oil system 30 includes an oil tank 41 constituted by a housing 40, a main conduit 50 for supplying oil, and a return conduit (not clearly shown) for returning the oil. Here, the continuously variable transmission 1, the tilt angle adjusting mechanism 2 for adjusting the drive angle of the continuously variable transmission 1 by adjusting the tilt angle of the power roller of the continuously variable transmission 1, and the tilt angle adjusting mechanism 2 are provided. The hydraulic servo mechanism 3 to be driven is housed in the housing 40.

  Specifically, the oil tank 41 includes a lower portion and an upper portion of the housing 40, and the lower portion functions as a normal-time oil tank 41a that supplies oil at a normal time. The oil tank 41b functions. Here, the normal time refers to a state where the acceleration of gravity is positive, and the negative time refers to a state where the acceleration of gravity is negative.

  The main pipeline 50 is configured so that oil can be supplied to the hydraulic servo mechanism 3, the bearing lubrication mechanism, the gear lubrication mechanism, the traction drive lubrication mechanism, the generator cooling mechanism, and the like both at normal time and at minus G time.

  Specifically, the main line 50 is connected to a supply pipe 51 having an oil suction port opened in the normal oil tank 41a, a first pump (for example, a scavenge pump) 52, and a first air separator 53 from the upstream side. A second pump (for example, a lubrication pump) 54, a filter 55, an oil cooler 56, and a second air separator 57 are interposed in this order. Then, oil is supplied to the supply pipe 51 on the discharge side of the first pump 52 at the time of minus G when the oil suction port is opened in the minus G hour oil tank 41b and the minus G hour pump 62 is interposed. A supply pipe 61 for minus G is connected. The supply pipe 51 is provided with temperature sensors Ti and To before and after the oil cooler 56. The first and second pumps 52 and 54 and the minus G hour pump 62 are driven by the output shaft of the engine via a driving force transmission mechanism.

  Here, the second air separator 57 is provided so that the air in the housing 40 is supplied in the zero-gravity state that occurs when shifting from the normal time to the minus G time or vice versa. This is to avoid instability of the hydraulic servomechanism 3 caused by the oil sucked by one pump 52 and the air sucked in.

  The air separators 53 and 57 are, for example, cyclone air separators.

  In addition, the filter 55 and the oil cooler 56 can use suitably the well-known thing used for various lubrication systems, and there is no limitation in particular in the structure.

  A relief valve 54 a is provided on the discharge side of the second pump 54. The relief oil from the relief valve 54 a is returned to the supply pipe 51 on the suction side of the first pump 52.

  The filter 55 is provided with a bypass 55a having a filter bypass valve 55b that bypasses the oil at low temperatures where the fluidity of the oil is low, and a pop-up indicator 55c that detects clogging of the filter 55.

  Further, on the downstream side of the air-containing oil outlet of the second air separator 57 of the supply pipe 51, a part of the oil containing air is supplied to the negative G hour supply pipe 61 on the suction side of the negative G hour pump 62. A return pipe 58 is provided to return to (1). A pressure regulating valve 58a is interposed in the return pipe 58 so that the pressure is constant. That is, an oil circulation system for circulating a part of the oil discharged from the second pump 54 is provided. Thus, by raising a part of the oil from the second air separator 57 back to the minus G hour supply pipe 61 on the suction side of the minus G hour pump 62 and circulating it, the temperature rise of the oil is promoted. .

  As shown in FIG. 1, the hydraulic control circuit 10 includes a hydraulic servo mechanism 3 that controls a tilt angle adjusting mechanism 2 that adjusts the tilt angle of the power roller of the continuously variable transmission 1.

  Specifically, the hydraulic control circuit 10 is an oil branched from an air separation oil outlet for sending air separation oil of the second air separator 57 interposed in the supply pipe 51 and air is separated and removed to the servo valve 3a. A servo valve pipe 11 for supplying the drive oil, a drive oil supply pipe 12 for supplying drive oil from the servo valve 3a to the hydraulic cylinder 2a of the tilt angle adjusting mechanism 2, and a drive oil from the hydraulic cylinder 2a for supplying the drive oil to the servo valve 3a. The drive oil return pipe 13 for returning to the main part is provided as a main part.

  As described above, since the hydraulic control circuit 10 is branched from the air separation oil outlet for sending the air separation oil of the second air separator 57, the hydraulic servo mechanism does not become unstable.

  The drive oil supply pipe 12 and the drive oil return pipe 13 are determined by the operating direction of the hydraulic cylinder 2a. That is, the pipe that has functioned as the drive oil supply pipe 12 when the piston of the hydraulic cylinder 2a advances functions as the drive oil return pipe 13 when the piston moves backward.

  As shown in FIG. 4, the servo valve 3 a includes a spool valve 3 b having a spool and a spool valve driving unit 3 c that slides the spool to adjust its position.

  The spool valve drive unit 3c adjusts the back pressure of the spool valve 3b to slide the spool, thereby adjusting the position of the spool. Specifically, the spool valve drive unit 3c includes a flapper that adjusts the back pressure of the spool valve 3b, an amateur integrated with the flapper, and an electromagnetic drive mechanism that displaces the amateur. An example of such a servo valve is a MOOG servo valve.

  The servo valve pipe 11 is provided with a hydraulic pump 14 for boosting the oil supplied to the servo valve 3a to a predetermined pressure and a filter 15 in this order from the branch point side (that is, upstream side). The filter 15 is used to prevent dust from entering the servo valve 3a.

  In the servo valve pipe 11 on the discharge side of the hydraulic pump 14, a relief valve 16 is provided to adjust the pressure of the pipe 11, and the relief oil from the relief valve 16 is supplied to the second air separator 57. It is returned to the supply pipe 51 on the upstream side. That is, a relief oil return pipe 17 is provided. In this way, by returning the relief oil to the upstream side of the second air separator 57, the temperature rise of the oil at a low temperature where the fluidity of the oil is poor is promoted, and the oil from which the air is removed even in the weightless state Can be supplied to the servo valve conduit 11. The filter 15 is provided with a filter pop-up indicator 15a.

  Further, on the downstream side of the servo valve pipe 11 where the filter 15 is provided, a warm fuse valve 21 having a flow fuse valve 21 is used to warm the servo valve 3a by spraying heated oil onto the servo valve 3a. A machine pipe 20 is provided. The flow fuseval 21 also has a function of protecting the hydraulic pump 14 by reducing the discharge pressure when the hydraulic pump has a low rotational speed.

  The oil discharge pipe 18 for discharging the oil from the servo valve 3a is configured so that the oil from the servo valve 3a is returned to the normal time oil tank 41a.

  Therefore, in the oil system 30 having such a configuration, oil is normally supplied in the direction indicated by the arrow in FIG. 2, and the hydraulic servo mechanism 3 is controlled by the hydraulic control circuit 10 to adjust the tilt angle of the power roller. While the gear ratio of the continuously variable transmission 1 is adjusted and adjusted, oil is supplied in the direction indicated by the arrow in FIG. 3 at minus G, and the hydraulic servo mechanism 3 is controlled by the hydraulic control circuit 10 to control the power roller. The gear ratio of the continuously variable transmission 1 is controlled by adjusting the tilt angle.

  Thus, in this embodiment, since the heated oil is sprayed onto the servo valve 3a to warm up the servo valve 3a, the continuously variable transmission 1 is not quickly started even in a cold region. obtain.

  Further, since the hydraulic control circuit 10 is branched from the oil circulation system, the heated oil can be quickly supplied to the hydraulic servo mechanism 3. This also has the effect of accelerating the warm-up of the servo valve 3a by the warm-up pipe 20.

  The present invention can be applied to a hydraulic control circuit of a toroidal continuously variable transmission.

It is an oil system diagram concerning one embodiment of the present invention. It is a perspective view of the same oil system diagram, and shows a flow of oil in normal time. It is a perspective view of the same oil system diagram, and shows the flow of oil at minus G. It is the schematic of the servo valve used for the hydraulic control circuit.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Continuously variable transmission 2 Tilt angle adjustment mechanism 3 Hydraulic servo mechanism 3a Servo valve 10 Hydraulic control circuit 11 Servo valve pipe 17 Relief oil return pipe 20 Warm-up pipe 21 Flow fuse valve 30 Oil system 40 Housing 41 Oil tank 41a Normal Oil tank for hour 41b Oil tank for minus G hour 50 Main pipeline 51 Supply pipe 57 Second air separator 61 Supply pipe for minus G hour

Claims (3)

A hydraulic control circuit for controlling a hydraulic servo mechanism of a continuously variable transmission,
In a hydraulic control circuit including a hydraulic pump that is disposed upstream of the hydraulic control circuit and boosts oil supplied to a servo valve of the hydraulic servo mechanism to a predetermined pressure;
A return pipe for raising the temperature of the oil by returning a part of the oil boosted by the hydraulic pump to the hydraulic pump;
A warm-up tube to warm up the sprayed can attach to the servo valve to the servo valve of the heating by the oil wherein the hydraulic servo mechanism,
A hydraulic control circuit for a continuously variable transmission, further comprising:   The hydraulic control circuit for a continuously variable transmission according to claim 1, wherein the warm-up pipe is provided with a flow fuse valve. 3. The hydraulic control circuit for a continuously variable transmission according to claim 1, wherein the hydraulic control circuit is branched from an oil circulation system.