JP2005195029A - Hydraulic circuit for internal combustion engine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a hydraulic circuit preventing a hydraulic pump from performing wasteful work and capable of attaining energy saving by suppressing power consumption as much as possible and of miniaturizing of the hydraulic pump. <P>SOLUTION: This hydraulic circuit for an internal combustion engine is provided with the hydraulic pump 23 comprising an internal gear pump, sucking working fluid inside an oil pan 6 and having two discharge ports 31, 32; a first discharge passage 36 guiding working fluid discharged from the first discharge port 31 of the hydraulic pump 23 and communicated with a main gallery 8; a second discharge passage 37 guiding working fluid discharged from the second discharge port 32 of the hydraulic pump 23 and communicated with a valve control device 19; a communication passage 39 communicating the second discharge port 37 with the first discharge port 36; and a relief valve 21 provided on the communication passage 39 and opened by predetermined pressure of the second discharge port 37. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a hydraulic circuit of an internal combustion engine that supplies hydraulic oil for lubrication of each part of the internal combustion engine, a control device for an air supply / exhaust valve, and the like.

This type of conventional hydraulic circuit has a first hydraulic pump and a second hydraulic pump that are independent of each other, and the first hydraulic pump sucks the hydraulic oil in the oil pan and communicates with the first discharge passage that communicates with the main gallery. The second hydraulic pump discharges the hydraulic oil in the discharge passage, further increases the pressure, and discharges it to the second discharge passage communicating with the valve control device (see Patent Document 1).
JP-A-4-175431.

  Each of the first discharge passage and the second discharge passage is provided with a relief passage communicating with the oil pan and a relief valve for opening the relief passage with a predetermined pressure. The first discharge passage and the second discharge passage Each of these is kept at a predetermined pressure.

  That is, a first relief passage communicating with the oil pan communicates with the first discharge passage, and a first relief valve that opens the first relief passage with a predetermined pressure of the first discharge passage is provided in the first relief passage. The pressure in the first discharge passage is maintained at a predetermined pressure by the relief operation of the first relief valve. The second discharge passage communicates with a second relief passage communicating with the oil pan. The second relief passage is provided with a second relief valve that opens the second relief passage with a predetermined pressure of the second discharge passage. The pressure in the second discharge passage is maintained at a predetermined pressure by the relief operation of the second relief valve.

  The hydraulic oil discharged to the first discharge passage is guided to the sliding portion of the internal combustion engine via the main gallery, and is provided for lubrication of the sliding portion, while the hydraulic oil discharged to the second discharge passage is It is guided to the valve control device and used for the operation of this valve control device.

  By the way, in the conventional example, the first relief passage communicating with the first discharge passage communicates with the oil pan, and the second relief passage communicating with the second discharge passage communicates with the oil pan. The first hydraulic pump requires a capacity capable of discharging an amount of hydraulic oil (Q1) necessary for lubricating the sliding portion of the internal combustion engine, and the second hydraulic pump has a discharge capacity (Q2) required for operating the valve control device. ) Is needed.

  However, the valve control device operates under a predetermined condition of the operating state of the internal combustion engine, and is inactive in the normal operating state, and the inside of the second discharge passage is predetermined by the relief operation of the second relief valve. Kept in pressure. That is, the second hydraulic pump always discharges the amount of hydraulic oil (Q2) necessary for the operation of the valve control device, but when the valve control device is not in operation, the second relief valve is opened to return to the oil pan. It will be.

  For this reason, in particular, the second hydraulic pump performs useless work because the hydraulic oil in the second discharge passage is recirculated to the oil pan when the valve control device is not in operation, and wasteful power consumption is caused. Will do.

  The present invention has been devised in view of the above-described conventional situation, and the hydraulic pump does not perform useless work, and can save energy by suppressing power consumption as much as possible. It is an object of the present invention to provide a hydraulic circuit capable of reducing the size of a pump.

  Accordingly, the invention described in claim 1 is composed of an inscribed gear pump, and includes a hydraulic pump having two discharge ports for sucking hydraulic oil in the oil pan, and a first discharge port of the hydraulic pump. A first discharge passage through which discharged hydraulic oil is guided and communicated with the main gallery; a second discharge passage through which hydraulic oil discharged from the second discharge port of the hydraulic pump is guided and communicated with the valve control device; A communication passage that communicates the second discharge passage and the first discharge passage, and a relief valve that is provided in the communication passage and opens at a predetermined pressure in the second discharge passage are provided.

  In the first aspect of the present invention, the hydraulic pump sucks the hydraulic oil in the oil pan and discharges it from the first discharge passage and the second discharge port to the first discharge passage and the second discharge passage. The hydraulic oil discharged from the first discharge port to the first discharge passage is guided to the sliding portion of the internal combustion engine through the main gallery, and is used for lubrication of the sliding portion. On the other hand, the hydraulic oil discharged from the second discharge port to the second discharge passage is guided to the valve control device and used for the operation of the valve control device.

  Here, when the valve control device is in the non-operating state, the hydraulic oil discharged from the second discharge port of the hydraulic pump to the second discharge passage passes through the communication passage under the relief operation by the relief valve. It flows into the first discharge passage.

  As a result, a flow rate (Qt = Q1 + Qa) obtained by adding a flow rate (Qa) flowing from the second discharge passage through the communication passage to the predetermined flow rate (Q1) discharged from the first discharge port in the first discharge passage. ) Hydraulic oil is led. Note that the flow rate (Qa) flowing from the second discharge passage into the first discharge passage when the valve control device is not operating is a discharge from the second discharge port because the actuator of the valve control device is substantially closed circuit. It becomes substantially equal to the capacity (Q2).

  For this reason, the total amount of hydraulic fluid that is guided from the first discharge passage to the sliding portion of the internal combustion engine via the main gallery and is used for lubrication of the sliding portion is Qt, and is supplied from the second discharge port to the second discharge port. The hydraulic oil guided to the two discharge passages is guided to the first discharge passage when the valve control device is not in operation, and the entire discharge capacity of the hydraulic pump is used without waste.

  Further, the hydraulic pump can be miniaturized correspondingly because the entire discharge capacity from the first discharge port and the second discharge port is used without waste.

  During the operation of the valve control device, the discharge oil from the second discharge port is used for the operation of the valve control device, so that the flow rate of the hydraulic oil guided to the first discharge passage is temporarily reduced. However, since the operation time of the valve control device is extremely short, and the hydraulic pressure in the first discharge passage is restored in a short time, it has a substantial influence on the lubrication of the sliding portion of the internal combustion engine. Absent.

  Therefore, the hydraulic pump does not perform useless work, and it is possible to achieve energy saving by suppressing power consumption as much as possible and to obtain a hydraulic circuit capable of reducing the size of the hydraulic pump. .

  According to a second aspect of the present invention, in the configuration of the first aspect of the present invention, the second discharge port is formed in front of the first discharge port in the rotational direction of the hydraulic pump.

  According to the second aspect of the invention, since the second discharge port is formed in front of the first discharge port in the rotation direction of the hydraulic pump, the second discharge port is operated at a higher pressure than the first discharge port. Oil will be led. For this reason, it is possible to easily guide the high-pressure hydraulic oil to the second discharge passage that requires high pressure to operate the valve control device, and to increase the total amount of hydraulic oil discharged from the hydraulic pump. Energy saving is achieved in comparison.

  Further, since the second discharge port is formed in front of the first discharge port in the rotation direction of the hydraulic pump, the increase in hydraulic pressure is faster in the first discharge port than in the second discharge port. That is, when starting the hydraulic pump, the hydraulic oil is introduced to the first discharge port earlier than the second discharge port.

  For this reason, when the internal combustion engine is stopped and then restarted, hydraulic oil can be supplied from the first discharge port to the sliding portion of the internal combustion engine at an early stage to lubricate the sliding portion. Since the valve control device does not operate immediately after the internal combustion engine is restarted, there is no problem caused by delaying the supply of hydraulic oil to the second discharge port rather than the first discharge port.

  According to the present invention, the hydraulic pump does not perform useless work, the power consumption can be suppressed as much as possible, energy saving can be achieved, and the hydraulic pump can be miniaturized. A circuit is obtained.

  A first embodiment according to the present invention includes a first hydraulic pump and a second hydraulic pump that are independent from each other, and a first discharge passage that is guided by hydraulic oil discharged from the first hydraulic pump and communicates with a main gallery. The hydraulic oil discharged from the second hydraulic pump is guided, the second discharge passage communicated with the valve control device, the communication passage communicating the second discharge passage and the first discharge passage, and the communication passage And a relief valve that opens the communication passage at a predetermined pressure in the second discharge passage.

  According to the first embodiment, the first hydraulic pump, for example, sucks hydraulic oil in an oil pan and discharges it to the first discharge passage. The hydraulic oil discharged to the first discharge passage is guided to the sliding portion of the internal combustion engine through the main gallery and is used for lubrication of the sliding portion. On the other hand, the second hydraulic pump, for example, sucks hydraulic oil in an oil pan and discharges it to the second discharge passage. The hydraulic oil discharged to the second discharge passage is guided to the valve control device and used for the operation of the valve control device.

  Here, when the valve control device is in the non-operating state, the hydraulic oil discharged from the second hydraulic pump to the second discharge passage is discharged through the communication passage under the relief operation by the relief valve. It flows into the passage.

  As a result, a flow rate (Qt = Q1 + Qa) obtained by adding a flow rate (Qa) flowing in from the second discharge passage through the communication passage to the predetermined flow rate (Q1) discharged from the first hydraulic pump in the first discharge passage. ) Hydraulic oil is led. Note that the flow rate (Qa) flowing from the second discharge passage into the first discharge passage when the valve control device is not operating is the discharge capacity of the second hydraulic pump because the actuator of the valve control device is substantially closed circuit. It is substantially equal to (Q2).

  For this reason, the total amount of hydraulic fluid that is guided from the first discharge passage to the sliding portion of the internal combustion engine through the main gallery and is used for lubrication of the sliding portion is Qt, and is supplied from the second hydraulic pump. Since the discharge oil is guided to the first discharge passage when the valve control device is not in operation, the second hydraulic pump does not perform useless work.

  Further, the first hydraulic pump only needs to have a discharge capacity corresponding to the amount obtained by subtracting the inflow amount (Qa) from the amount of hydraulic oil (Qt) necessary for lubricating the sliding portion of the internal combustion engine. Can be miniaturized.

  During the operation of the valve control device, the discharge oil from the second hydraulic pump is used for the operation of the valve control device, so that the flow rate of the hydraulic oil guided to the first discharge passage is temporarily reduced. However, since the operation time of the valve control device is extremely short, and the hydraulic pressure in the first discharge passage is restored in a short time, it has a substantial influence on the lubrication of the sliding portion of the internal combustion engine. Absent.

  Therefore, the hydraulic pump does not perform useless work, and it is possible to achieve energy saving by suppressing power consumption as much as possible and to obtain a hydraulic circuit capable of reducing the size of the hydraulic pump. .

  Further, in the configuration of the first embodiment, each of the first discharge passage and the second discharge passage is provided with a filter, and the first discharge passage and the second discharge passage on the upstream side of these filters. Are communicated with each other through a communication passage.

  According to this configuration, the first discharge passage and the second discharge passage are each provided with a filter, so that the hydraulic oil is filtered by these filters to the sliding portion of the internal combustion engine and the valve control device. Clean hydraulic oil can be supplied.

  In the second embodiment of the present invention, a hydraulic pump having two discharge ports and a first discharge passage through which hydraulic oil discharged from the first discharge port of the hydraulic pump is guided and communicated with the main gallery. Hydraulic oil discharged from the second discharge port of the hydraulic pump, a second discharge passage communicating with the valve control device, a communication passage communicating the second discharge passage and the first discharge passage, A relief valve is provided in the communication passage and opens at a predetermined pressure in the second discharge passage.

  In such a configuration, the hydraulic pump, for example, sucks hydraulic oil in the oil pan and discharges the hydraulic oil from the first discharge port and the second discharge port to the first discharge passage and the second discharge passage. The hydraulic oil discharged from the first discharge port to the first discharge passage is guided to the sliding portion of the internal combustion engine through the main gallery, and is used for lubrication of the sliding portion. On the other hand, the hydraulic oil discharged from the second discharge port to the second discharge passage is guided to the valve control device and used for the operation of the valve control device.

  Here, when the valve control device is in the non-operating state, the hydraulic oil discharged from the second discharge port of the hydraulic pump to the second discharge passage passes through the communication passage under the relief operation by the relief valve. It flows into the first discharge passage.

  As a result, a flow rate (Qt = Q1 + Qa) obtained by adding a flow rate (Qa) flowing from the second discharge passage through the communication passage to the predetermined flow rate (Q1) discharged from the first discharge port in the first discharge passage. ) Hydraulic oil is led. Note that the flow rate (Qa) flowing from the second discharge passage into the first discharge passage when the valve control device is not operating is a discharge from the second discharge port because the actuator of the valve control device is substantially closed circuit. It becomes substantially equal to the capacity (Q2).

  For this reason, the total amount of hydraulic fluid that is guided from the first discharge passage to the sliding portion of the internal combustion engine via the main gallery and is used for lubrication of the sliding portion is Qt, and is supplied from the second discharge port to the second discharge port. The hydraulic oil guided to the two discharge passages is guided to the first discharge passage when the valve control device is not in operation, and the entire discharge capacity of the hydraulic pump is used without waste.

  Further, the hydraulic pump can be miniaturized correspondingly because the entire discharge capacity from the first discharge port and the second discharge port is used without waste.

  During the operation of the valve control device, the discharge oil from the second discharge port is used for the operation of the valve control device, so that the flow rate of the hydraulic oil guided to the first discharge passage is temporarily reduced. However, since the operation time of the valve control device is extremely short, and the hydraulic pressure in the first discharge passage is restored in a short time, it has a substantial influence on the lubrication of the sliding portion of the internal combustion engine. Absent.

  Therefore, the hydraulic pump does not perform useless work, and it is possible to achieve energy saving by suppressing power consumption as much as possible and to obtain a hydraulic circuit capable of reducing the size of the hydraulic pump. .

  In the configuration of the second embodiment, each of the first discharge passage and the second discharge passage is provided with a filter, and the first discharge passage and the second discharge passage on the upstream side of these filters. Are communicated with each other through a communication passage.

  In addition, according to this configuration, the first discharge passage and the second discharge passage are each provided with a filter, so that the hydraulic oil is filtered by these filters, and the sliding portion and the valve control of the internal combustion engine are filtered. Clean hydraulic fluid can be supplied to the device.

  Further, in the configuration of the second embodiment, the hydraulic pump having the two discharge ports is constituted by an inscribed gear pump, and the second discharge port is rotated by the hydraulic pump more than the first discharge port. It is the structure formed ahead of the direction.

  According to such a configuration, the hydraulic pump having the two discharge ports is constituted by an inscribed gear pump, and the second discharge port is formed ahead of the first discharge port in the rotation direction of the hydraulic pump. Therefore, hydraulic oil having a pressure higher than that of the first discharge port is guided to the second discharge port. For this reason, it is possible to easily guide the high-pressure hydraulic fluid to the second discharge passage that requires high pressure for the operation of the valve control device, and in comparison with the case where the total amount of hydraulic oil discharged from the hydraulic pump is high. This saves energy.

  Further, since the second discharge port is formed in front of the first discharge port in the rotation direction of the hydraulic pump, the increase in hydraulic pressure is faster in the first discharge port than in the second discharge port. That is, when starting the hydraulic pump, the hydraulic oil is introduced to the first discharge port earlier than the second discharge port. For this reason, when the internal combustion engine is stopped and then restarted, hydraulic oil can be supplied from the first discharge port to the sliding portion of the internal combustion engine at an early stage to lubricate the sliding portion. Since the valve control device does not operate immediately after the internal combustion engine is restarted, there is no problem caused by delaying the supply of hydraulic oil to the second discharge port rather than the first discharge port.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

  FIG. 1 is an explanatory diagram of a hydraulic circuit of an internal combustion engine showing an embodiment of the present invention.

  In the figure, 1 is a first hydraulic pump, 2 is a second hydraulic pump, and these first hydraulic pump 1 and second hydraulic pump 2 are independent of each other, and are linked to each other or in conjunction with an internal combustion engine not shown. Driven by rotation.

  3 is a first suction passage for the first hydraulic pump 1, and 4 is a first discharge passage. The first suction passage 3 is provided with an oil strainer 5 at its tip and communicates with an oil pan 6. As a result, the first hydraulic pump 1 can suck the hydraulic oil in the oil pan 6 through the first suction passage 3 and discharge it into the first discharge passage 4.

  The first discharge passage 4 communicates with the main gallery 8 via a filter 7, and the hydraulic oil guided to the main gallery 8 is guided to the sliding portion 9 of the internal combustion engine, and the sliding portion 9 is passed through the sliding portion 9. It is possible to lubricate.

  A communication passage 10 communicates the first suction passage 3 and the first discharge passage 4. The communication passage 10 is provided with a relief valve 11 that opens the communication passage 10 with a predetermined pressure of the first discharge passage 4. ing. For this reason, the inside of the first discharge passage 4 is maintained at a predetermined pressure by the relief operation of the relief valve 11.

  Reference numeral 13 denotes a second suction passage for the second hydraulic pump 2, and 14 denotes a second discharge passage. The second suction passage 13 is provided with an oil strainer 15 at the tip thereof and communicates with the oil pan 6. As a result, the second hydraulic pump 2 can suck the hydraulic oil in the oil pan 6 through the second suction passage 13 and discharge it into the second discharge passage 14.

  The second discharge passage 14 communicates with a valve control device 19 through a filter 17, and the hydraulic oil guided to the valve control device 19 can operate the valve control device 19. .

  A communication passage 20 communicates the second discharge passage 14 and the first discharge passage 4. The communication passage 20 is provided with a relief valve 21 that opens the communication passage 20 with a predetermined pressure in the second discharge passage 14. For this reason, the inside of the second discharge passage 14 is maintained at a predetermined pressure by the relief operation of the relief valve 21.

  In such a configuration, the first hydraulic pump 1 and the second hydraulic pump 2 are rotationally driven by an internal combustion engine. The first hydraulic pump 1 sucks hydraulic oil in the oil pan 6 through the first suction passage 3 and discharges it to the first discharge passage 4. The hydraulic oil discharged to the first discharge passage 4 is guided to the main gallery 8 through the filter 7, and further guided from the main gallery 8 to the sliding portion 9 of the internal combustion engine to lubricate the sliding portion 9. To be served. On the other hand, the second hydraulic pump 2 sucks the hydraulic oil in the oil pan 6 through the second suction passage 13 and discharges it to the second discharge passage 14. The hydraulic oil discharged to the second discharge passage 14 is guided to the valve control device 19 through the filter 17 and is used for the operation of the valve control device 19.

  Here, when the valve control device 19 is in the non-operating state, the hydraulic oil discharged from the second hydraulic pump 2 to the second discharge passage 14 is connected to the communication passage 20 under the relief operation by the relief valve 21. Through the first discharge passage 4.

  As a result, the flow rate obtained by adding the flow rate (Qa) flowing from the second discharge passage 14 via the communication passage 20 to the predetermined flow rate (Q1) discharged from the first hydraulic pump 1 to the first discharge passage 4. The hydraulic oil (Qt = Q1 + Qa) is guided. The flow rate (Qa) flowing into the first discharge passage 4 from the second discharge passage 14 when the valve control device 19 is not in operation is the second hydraulic pressure because the actuator of the valve control device 19 is substantially closed circuit. It becomes approximately equal to the discharge capacity (Q2) of the pump 2.

  For this reason, the total amount of hydraulic fluid that is guided from the first discharge passage 4 to the sliding portion 9 of the internal combustion engine through the main gallery 8 and is used for lubrication of the sliding portion 9 is Qt, Since the discharge oil from the hydraulic pump 2 is guided to the first discharge passage 4 when the valve control device 19 is not operated, the second hydraulic pump 2 does not perform useless work.

  The first hydraulic pump 1 only needs to have a discharge capacity equal to the amount obtained by subtracting the inflow amount (Qa) from the amount of hydraulic oil (Qt) necessary for lubricating the sliding portion 9 of the internal combustion engine. The hydraulic pump 1 can be downsized.

  During the operation of the valve control device 19, the discharge oil from the second hydraulic pump 2 is used for the operation of the valve control device 19, so the flow rate of the hydraulic oil that is temporarily guided to the first discharge passage 4. However, since the operating time of the valve control device 19 is extremely short and the hydraulic pressure in the first discharge passage 4 is restored in a short time, the lubrication of the sliding portion 9 of the internal combustion engine is substantially achieved. There is no negative impact.

  Therefore, the hydraulic pump does not perform useless work, and it is possible to achieve energy saving by suppressing power consumption as much as possible and to obtain a hydraulic circuit capable of reducing the size of the hydraulic pump. .

  Further, the first discharge passage 4 and the second discharge passage 14 are provided with a filter 7 and a filter 17, respectively, so that the hydraulic oil is filtered by the filters 7 and 17 so as to slide the internal combustion engine. 9 and the valve control device 19 can be supplied with clean hydraulic fluid.

  2 and 3 are drawings showing another embodiment of the present invention, FIG. 2 is an explanatory view of a hydraulic circuit, and FIG. 3 is a sectional view of the hydraulic pump shown in FIG. This embodiment will be described below.

  In the figure, reference numeral 23 denotes a hydraulic pump. The hydraulic pump 23 includes two discharge ports as will be described later, and is driven to rotate by an internal combustion engine (not shown).

  In this embodiment, the hydraulic pump 23 is an inscribed gear pump. That is, in a circular recess 25 formed in the pump housing 24, a ring-shaped first gear-shaped member 27 having inner teeth 26 on the inner periphery and an outer gear meshing with the inner teeth 26 of the first gear-shaped member 27. A second gear-like member 29 having teeth 28 is rotatably accommodated.

  The pump housing 24 includes a body 24a and a cover (not shown). A suction port 30, a first discharge port 31, and a second discharge port 32 are opened in a recess 25 formed in the pump housing 24. The suction port 30 is in a region where the meshing clearance between the inner teeth 26 of the first gear-like member 27 and the outer teeth 28 of the second gear-like member 29 increases as the first gear-like member 27 rotates. Similarly, the first discharge port 31 and the second discharge port 32 are open toward the region where the meshing gap decreases.

  The second discharge port 32 is formed in front of the first discharge port 31 in the rotation direction of the hydraulic pump 23 (the rotation direction of the first gear-like member 27 and the second gear-like member 29).

  The first gear-like member 27 is rotatably accommodated in the recess 25 of the pump housing 24, and the internal teeth 26 formed on the inner periphery of the first gear-like member 27 are based on a trochoidal curve. It has a tooth profile shape consisting of a high-order function curve, and is formed over the entire width in the axial direction.

  The second gear-shaped member 29 is connected to the drive shaft 33 and is arranged slightly eccentric with respect to the first gear-shaped member 27. The external teeth 28 formed on the outer periphery of the second gear-shaped member 29 are: Similar to the internal teeth 26 of the first gear-shaped member 27, it has a tooth profile formed of a high-order function curve based on a trochoid curve and is formed over the entire width in the axial direction. The number of teeth of the external teeth 28 of the second gear-shaped member 29 is 11 less than the number of teeth of 12 of the internal teeth 26 of the first gear-shaped member 27.

  A suction passage 35 communicates with the suction port 30 of the hydraulic pump 23. A first discharge passage 36 communicates with the first discharge port 31 of the hydraulic pump 23, and a second discharge passage 37 similarly communicates with the second discharge port 32. The suction passage 35 is provided with an oil strainer 38 at the tip thereof and communicates with the oil pan 6. As a result, the hydraulic pump 23 sucks the hydraulic oil in the oil pan 6 through the suction passage 35 and the suction port 30 and discharges it to the first discharge passage 36 through the first discharge port 31. It is possible to discharge to the second discharge passage 37 via the discharge port 32.

  The first discharge passage 36 communicates with the main gallery 8 via the filter 7, and the hydraulic oil guided to the main gallery 8 is guided to the sliding portion 9 of the internal combustion engine, and the sliding portion 9 is It is possible to lubricate.

  Reference numeral 39 denotes a communication passage that allows the suction passage 35 and the first discharge passage 36 to communicate with each other. The communication passage 39 is provided with a relief valve 11 that opens the communication passage 39 with a predetermined pressure of the first discharge passage 36. . Therefore, the inside of the first discharge passage 36 is kept at a predetermined pressure by the relief operation of the relief valve 11.

  The second discharge passage 37 communicates with the valve control device 19 via the filter 17, and the hydraulic fluid guided to the valve control device 19 can operate the valve control device 19. .

  A communication passage 40 communicates the second discharge passage 37 and the first discharge passage 36. The communication passage 40 is provided with a relief valve 21 that opens the communication passage 40 with a predetermined pressure in the second discharge passage 37. For this reason, the inside of the second discharge passage 37 is maintained at a predetermined pressure by the relief operation of the relief valve 21.

  In such a configuration, the hydraulic pump 23 is rotationally driven by an internal combustion engine. When the second gear-like member 29 is rotated clockwise in FIG. 3 by the drive shaft 33, the hydraulic pump 23 sucks the working oil in the oil pan 6 through the suction passage 35 and the suction port 30, and the first Discharge from the discharge port 31 and the second discharge port 32 to the first discharge passage 36 and the second discharge passage 37, respectively.

  At this time, the hydraulic pump 23 conveys the hydraulic oil guided from the suction port 30 through the tooth groove of the inner tooth 26 of the first gear-like member 27 and the tooth groove of the outer tooth 28 of the second gear-like member 29. Then, the liquid is discharged to the first discharge port 31 and the second discharge port 32.

  The hydraulic oil discharged from the first discharge port 31 to the first discharge passage 36 is guided to the main gallery 8 through the filter 7, and is further guided from the main gallery 8 to the sliding portion 9 of the internal combustion engine. The sliding portion 9 is used for lubrication. On the other hand, the hydraulic oil discharged from the second discharge port 32 to the second discharge passage 37 is guided to the valve control device 19 through the filter 17 and is used for the operation of the valve control device 19.

  Here, when the valve control device 19 is in the non-operating state, the hydraulic oil discharged from the second discharge port 32 of the hydraulic pump 23 to the second discharge passage 37 is under the relief operation of the relief valve 21. It flows into the first discharge passage 36 via the communication passage 40.

  As a result, the flow rate (Qa) flowing from the second discharge passage 37 via the communication passage 40 to the predetermined flow rate (Q1) discharged from the first discharge port 31 is added to the first discharge passage 36 ( The hydraulic fluid of Qt = Q1 + Qa) will be led. Note that the flow rate (Qa) flowing from the second discharge passage 37 into the first discharge passage 36 when the valve control device 19 is not operating is the second discharge because the actuator of the valve control device 19 is substantially closed circuit. It becomes substantially equal to the discharge capacity (Q2) from the port 32.

  For this reason, the total amount of hydraulic oil that is guided from the first discharge passage 36 to the sliding portion 9 of the internal combustion engine through the main gallery 8 and is used for lubrication of the sliding portion 9 is Qt, The hydraulic fluid guided from the discharge port 32 to the second discharge passage 37 is guided to the first discharge passage 36 when the valve control device 19 is not in operation, and the entire discharge capacity of the hydraulic pump 23 is used without waste. become.

  Further, the hydraulic pump 23 can be miniaturized correspondingly because the entire discharge capacity from the first discharge port 31 and the second discharge port 32 is used without waste.

  During the operation of the valve control device 19, since the discharge oil from the second discharge port 32 is used for the operation of the valve control device 19, the flow rate of the hydraulic oil that is temporarily guided to the first discharge passage 36. However, since the operation time of the valve control device 19 is extremely short and the hydraulic pressure in the first discharge passage 36 is restored in a short time, the lubrication of the sliding portion 9 of the internal combustion engine is substantially achieved. There is no negative impact.

  Therefore, the hydraulic pump does not perform useless work, and it is possible to achieve energy saving by suppressing power consumption as much as possible and to obtain a hydraulic circuit capable of reducing the size of the hydraulic pump. .

  Further, since the first discharge passage 36 and the second discharge passage 37 are provided with the filter 7 and the filter 17, respectively, the working oil is filtered by the filters 7, 17, so that the sliding portion of the internal combustion engine can be obtained. 9 and the valve control device 19 can be supplied with clean hydraulic fluid.

  In addition, the hydraulic pump 23 having the two discharge ports 31 and 32 is constituted by an inscribed gear pump, and the second discharge port 32 is rotated in the direction of rotation of the hydraulic pump 23 (the first direction) than the first discharge port 31. Therefore, hydraulic oil having a pressure higher than that of the first discharge port 31 is guided to the second discharge port 32. For this reason, it is possible to easily guide the high-pressure hydraulic oil to the second discharge passage 37 that requires high pressure for the operation of the valve control device 19 and to make the total amount of discharge oil of the hydraulic pump 23 high. Energy saving can be achieved compared to

  Further, since the second discharge port 32 is formed in front of the first discharge port 31 in the rotation direction of the hydraulic pump, the increase in hydraulic pressure is faster in the first discharge port 31 than in the second discharge port 32. Become. That is, hydraulic oil is introduced to the first discharge port 31 earlier than the second discharge port 32 when the hydraulic pump is started. For this reason, when the internal combustion engine is stopped and then restarted, hydraulic oil can be supplied from the first discharge port 31 to the sliding portion 9 of the internal combustion engine at an early stage to lubricate the sliding portion 9. . Since the valve control device 19 does not operate immediately after the internal combustion engine is restarted, there is no problem caused by the delay in the supply of hydraulic oil to the second discharge port 32 rather than the first discharge port 31.

  Although the embodiment has been described with reference to the drawings, the specific configuration is not limited to this embodiment and can be changed without departing from the gist of the invention. For example, in the embodiment shown in FIGS. 2 and 3, the hydraulic pump 23 may be an internal gear pump of a type in which a crescent is provided between a ring-shaped outer rotor and an inner rotor. Further, the teeth formed on the first gear-like member 27 and the second gear-like member 29 are not limited to teeth having a trochoidal curve, but correspond to teeth having an involute curve, a sine curve, or the like. You may have a part, for example, a roller.

  According to the present invention, there is provided a hydraulic circuit capable of achieving energy saving by suppressing power consumption as much as possible without causing the hydraulic pump to perform useless work and reducing the size of the hydraulic pump. Therefore, it is suitable for a hydraulic circuit for supplying hydraulic oil for lubrication of each part of the internal combustion engine, a control device for the supply / exhaust valve, and the like.

It is explanatory drawing of the hydraulic circuit of the internal combustion engine which shows embodiment of this invention. It is explanatory drawing of the hydraulic circuit of the internal combustion engine which shows another embodiment of this invention. It is sectional drawing of the hydraulic pump shown in FIG.

Explanation of symbols

6 Oil pan 8 Main gallery 21 Relief valve 23 Hydraulic pump 31 1st discharge port 32 2nd discharge port 36 1st discharge path 37 2nd discharge path 39 Communication path

Claims (2)

A hydraulic pump composed of an internal gear pump, which sucks hydraulic oil in an oil pan and has two discharge ports;
Hydraulic oil discharged from the first discharge port of the hydraulic pump is guided, and the first discharge passage communicates with the main gallery;
Hydraulic oil discharged from the second discharge port of the hydraulic pump is guided, and the second discharge passage communicates with the valve control device;
A communication passage communicating the second discharge passage and the first discharge passage;
A relief valve provided in the communication passage and opened at a predetermined pressure in the second discharge passage;
A hydraulic circuit for an internal combustion engine, comprising: 2. The hydraulic circuit for an internal combustion engine according to claim 1, wherein the second discharge port is formed in front of the first discharge port in the rotation direction of the hydraulic pump.

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