JP4402067B2 - 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 specifically, the present invention relates to a hydraulic control circuit that controls the driving of a continuously variable transmission used in a power generator driven by an engine.

  2. Description of the Related Art Conventionally, a power generator driven by an engine output of an aircraft is known as an aircraft power generator. 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, in aircraft, the acceleration of gravity may change from plus to minus due to the influence of airflow during flight, and vice versa, and the hydraulic servo mechanism that operates the tilt angle during those transition periods There is a problem in that a predetermined amount of oil is not supplied to the hydraulic control circuit that controls the operation, and the operation of the hydraulic servo mechanism becomes unstable.

  In addition, even when the amount of oil supply is insufficient, a predetermined amount of oil is not supplied to the hydraulic control circuit that similarly controls the hydraulic servo mechanism, and the operation of the hydraulic servo mechanism becomes unstable. is there.

  The present invention has been made in view of the problems of the prior art, and when the acceleration of gravity changes from positive to negative during flight or vice versa, or the air is mixed into the oil, or the oil It is an object of the present invention to provide a hydraulic control circuit for a continuously variable transmission that does not cause unstable operation of the continuously variable transmission even when the supply of power is insufficient.

A hydraulic control circuit for a continuously variable transmission according to the present invention is a hydraulic control circuit for controlling a hydraulic servomechanism of a continuously variable transmission, and the oil supply pipe (51) from which the hydraulic control circuit (10) is branched. A first air separator (53), a lubrication pump (54) and a second air separator (57) for separating and removing air in the oil are interposed in this order from the upstream side on the upstream side of the branch. A hydraulic control circuit (10) is branched from an air separation oil outlet for sending out oil separated by the second air separator (57), and a hydraulic pump (14) is connected to the air separation oil outlet. An oil return pipe (17) for returning a predetermined amount of oil from the discharge side of the hydraulic pump (14) to the upstream side of the second air separator in the oil supply pipe (51 ) is provided.

  According to the present invention, a predetermined amount of oil is supplied to the hydraulic control circuit even when the acceleration of gravity changes from positive to negative during flight, or vice versa, and even when the amount of oil supply is insufficient. As a result, an excellent effect of not causing unstable operation of the hydraulic servo mechanism can be obtained.

  Further, according to a preferred embodiment of the present invention in which the hydraulic control circuit is branched from the air separation oil outlet from which the air is separated by the air separator, the air contained in the oil is separated during the transition period. An excellent effect is obtained that instability of the hydraulic servo mechanism due to pressure fluctuation is avoided.

  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.

  A hydraulic control circuit (hereinafter simply referred to as a hydraulic control circuit) 10 of an aircraft toroidal 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 oil system 30 to include is shown in FIGS. In addition, since the continuously variable transmission 1 and the tilt angle adjusting mechanism 2 can use a well-known thing suitably, the detailed description of the structure is abbreviate | 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 is configured by a lower portion and an upper portion of the housing 40, and the lower portion functions as a normal oil tank 41a that supplies oil in a normal state (when the acceleration of gravity is positive). Functions as an oil tank 41b for minus G when oil is supplied when minus G (when the acceleration of gravity is minus).

  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, the oil supply pipe 51 on the discharge side of the first pump 52 has the oil intake port opened in the oil tank 41b for the minus G hour, and the minus G hour oil in which the minus G hour pump 62 is interposed is provided. A supply pipe 61 for supplying 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 when the gravity acceleration is shifted from the normal state to the negative G time when the gravity acceleration is negative, or vice versa. This is to prevent the first pump 52 from sucking the air in the housing 40 in the zero gravity state that occurs in the transitional period when returning from time to time and causing the hydraulic servo mechanism 3 to become unstable due to the oil sucked in the air.

  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 oil 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. In this way, by raising a part of the oil from the second air separator 57 to the supply pipe 51 on the suction side of the second pump 54 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 for a servo valve that supplies oil from which air has been separated and removed from the air separation oil outlet of the second air separator 57 interposed in the supply pipe 51 to the servo valve 3a. A pipe 11, 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 return pipe for returning the drive oil from the hydraulic cylinder 2a to the servo valve 3a. 13 as a main part. 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.

  A relief valve 16 is provided in the discharge-side servo valve pipe 11 of the hydraulic pump 14 to adjust the pressure of the pipe 11 and to supply a predetermined amount of oil to the hydraulic control circuit 10 in the transition period. The relief oil from the relief valve 16 is returned to the supply pipe 51 on the upstream side of the second air separator 57. That is, a relief oil return pipe 17 is provided. In this way, by returning a predetermined amount of 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 low is promoted, and in the transition period in which the weightless state occurs. However, the oil from which the air has been removed can be supplied to the servo valve pipe 11, so that the hydraulic servo mechanism 3 does not become unstable due to insufficient supply of oil. The filter 15 is provided with a filter pop-up indicator 15a.

  A flow fuse valve 21 is provided on the downstream side of the servo valve pipe 11 where the filter 15 is provided in order to warm the servo valve 3a by spraying heated oil onto the servo valve 3a. A warm-up pipe 20 is provided.

  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.

  As described above, in this embodiment, a predetermined amount of oil is returned from the hydraulic control circuit 10 to the upstream side of the supply pipe 51 from which the hydraulic control circuit 10 is branched. A predetermined amount of oil is supplied to the hydraulic control circuit 10. Therefore, operation instability of the hydraulic servo mechanism 3 due to insufficient oil supply does not occur.

  As mentioned above, although this invention has been demonstrated based on embodiment, this invention is not limited only to this embodiment, A various change is possible. For example, although the embodiment has been described with an example applied to an aircraft continuously variable transmission, the application of the present invention is not limited to an aircraft continuously variable transmission, and is a continuously variable transmission driven by various engines. Applicable to the machine.

  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 line 17 Relief oil return pipe 20 Warm air 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 (1)

A hydraulic control circuit for controlling a hydraulic servo mechanism of a continuously variable transmission,
A first air separator (53), a lubrication pump (54), and a second air for separating and removing air in the oil on the upstream side of the branch of the oil supply pipe (51) from which the hydraulic control circuit (10) is branched. A separator (57) is interposed in this order from the upstream side,
The hydraulic control circuit (10) is branched from an air separation oil outlet for sending out oil separated by the second air separator (57), and a hydraulic pump (14) is connected to the air separation oil outlet. And an oil return pipe (17) for returning a predetermined amount of oil from the discharge side of the hydraulic pump (14) to the upstream side of the second air separator in the oil supply pipe (51). Hydraulic control circuit for continuously variable transmission.