JP2003027912A - Combination pump - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an integrated combination pump capable of adjusting the basic oil discharge pressure by a vane type variable displacement pump while ensuring the basic oil discharge pressure by a power pump driven by the driving force of the engine. SOLUTION: The combination pump 1 comprises a cycloid pump 2 as a first pump and a vane pump 9 as a second pump, and a pump housing is shared. The cycloid pump 2 uses the driving force of a crankshaft, and the vane pump 9 uses the driving force of the cycloid pump 2. The maximum capacity of the first pump can be reduced thereby, and adequate oil discharge pressure and adequate oil discharge quantity is ensured by operating the vane pump 9 as an auxiliary pump in an operation range in which the oil discharge pressure only by the first pump is insufficient.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to an oil pump for an internal combustion engine and a method of using the oil pump.

[0002]

2. Description of the Related Art Conventionally, as an oil pump used for lubricating an internal combustion engine, for example, a trochoid pump as disclosed in Japanese Patent Laid-Open No. 10-77817 is known. In this trochoid pump, its pump shaft rotates by receiving the driving force of the crankshaft of the internal combustion engine, and an oil discharge amount and hydraulic pressure that are proportional to the rotation speed of the internal combustion engine (hereinafter referred to as engine) are generated. Therefore, when the relief valve provided at the discharge port of the pump detects a predetermined pressure value of the discharge pressure or more, the valve is opened to communicate the discharge port with the suction port, and part of the oil at the discharge port is sucked into the suction port. I am going to return it to.
This prevents damage to the engine lubrication system and oil leakage.

[0003]

According to such a conventional oil pump, the excess of the oil is returned to the low pressure side through the relief valve at the time of high speed rotation to prevent damage to the engine lubricating system and prevent oil leakage. . Therefore, when rotating at high speed, there is a loss of mechanical energy that overcomes the spring biasing force of the relief valve and pushes the valve element, and drive energy that causes the excess oil pumped by the oil pump to return to the low pressure side and circulate oil. ing. Therefore, the fuel consumption efficiency of the engine decreases,
Not only that, but it also causes engine vibration and noise. On the other hand, if the maximum oil pressure value and maximum oil discharge amount of the oil pump are set so that a small amount of excess oil is returned to the low pressure side through the relief valve when the engine is rotating at high speed, the desired oil pressure value and oil amount are set when the engine is rotating at low speed. There is a problem that the discharge amount cannot be obtained, and the hydraulic pressure value and the oil discharge amount are insufficient. Especially when the engine is idling at a high temperature, the engine oil pressure has the lowest value, so there is a problem that the oil pressure value and oil discharge amount of the engine bearing, valve train, and other oil circulation systems become insufficient. is there.

Further, the vane type pump disclosed in Japanese Unexamined Patent Publication No. 6-185475 utilizes the fact that the number of vanes contacting the cylindrical member decreases as the number of rotations of the rotor increases, and the discharge amount is controlled. Are doing All the vanes are in contact with the columnar member in the low speed rotation region, and when the rotational speed of the rotor gradually increases from this low speed rotation region, the vane furthest from the columnar member first separates from the columnar member. When the rotor speed further increases,
The number of vanes in contact with the cylindrical member is reduced. Therefore,
Since the difference between the maximum volume and the minimum volume of the pump chamber is small,
When the rotor rotates at high speed, the amount of oil that can be pumped is extremely reduced. Also, if the spring load is increased so that a predetermined number of vanes can contact the columnar member even in the high-speed rotation range, the rotational speed of the rotor required to separate the vane from the columnar member and reduce the pump discharge rate increases, so excess oil Leading to the occurrence of.

An object of the present invention is to provide a composite pump which can secure a desired oil discharge pressure and a desired oil discharge amount in a low speed rotation range and can minimize energy loss in a medium speed or high speed rotation range.

Another object of the present invention is to provide an integral type composite pump capable of adjusting the basic oil discharge pressure by means of a vane type variable displacement pump while ensuring the basic oil discharge pressure by means of a power pump driven by the driving force of the engine. To provide. Still another object of the present invention is to provide an integrated composite pump which uses a power pump driven by a driving force output from an engine as a main pump and a vane type variable displacement pump controllable by an electric operation signal as an auxiliary pump. To provide.

[0007]

According to another aspect of the present invention, there is provided a vane type pump having a vane which is retracted at a high speed by centrifugal force in addition to a power hoop which is rotated by a drive shaft of an engine. By arranging and in parallel, desired oil can be secured even when the engine is rotating at a low speed.

According to the composite pump of the second aspect, it is possible to allow oil to flow only from the vane pump side to the power hoop side in the oil passage connecting the discharge port of the power hoop and the discharge port of the vane type pump. Since the check valve is provided, it is possible to prevent the reverse flow of oil.

According to the composite pump of the third aspect, since the gear pump is used for the power pump, the reliability is high, and the power pump constantly discharges oil, so that the possibility of insufficient lubrication is small.

According to the composite pump of the fifth aspect, since the vanes are provided inside and outside the cam rotor, respectively, the first vane pump and the second vane pump can be accommodated in a small volume.

According to the sixth aspect of the present invention, since the vane position of the vane pump is controlled by the electromagnetic force of the coil portion arranged on the cam rotor side, the oil discharge amount can be precisely controlled.

According to the composite pump of the seventh aspect, since the position of the vane of the vane pump is controlled by the magnetic force of the magnetic force generator disposed on the side of the column, the oil discharge amount can be precisely controlled.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings. (First Embodiment) A composite pump to which the present invention is applied is shown in FIGS. 1, 2 and 3. As shown in FIGS. 1 and 2, the composite pump 1 includes a cycloid pump 2 and a vane pump 9 which are arranged in parallel.

The cycloid pump 2 as a first pump has a drive shaft 3 which is directly or indirectly connected to a crankshaft of an engine and rotates in synchronization with the crankshaft. The drive shaft 3 has a drive rotor as an inner rotor. 4 is attached. A driven rotor 5 as an outer rotor is rotatably supported by an inner wall 22 of the pump housing 1 outside the drive rotor 4. The number of four external teeth formed on the peripheral portion of the drive rotor 4 is one less than the number of internal teeth of the driven rotor 5 in this case. When the drive rotor 4 rotates in the direction of the arrow, the driven rotor 5 also rotates in the same direction due to the meshing of the inner teeth and the outer teeth, so that the first pump chamber 20 moves from the suction port 6 to the first pump chamber 20.
The oil that has entered is supplied to the discharge port 7 as the volume of the pump chamber changes. The oil flowing into the suction port 6 is
Is injected into the pump chamber between the outer teeth of the driven rotor 5 and the inner teeth of the driven rotor 5, and the oil in the pump chamber is supplied to the discharge port 7 as the drive shaft 3 rotates, and the oil is discharged from the discharge port 7.

The vane pump 9 as the second pump is
It has a drive shaft 17. Gear 19 fixed to drive shaft 17
Engages with a gear 18 fixed to the drive shaft 3 of the cycloid pump 2, and receives the driving force of the drive shaft 3 to rotate. The cam rotor 12 fixed to the drive shaft 17 is
A predetermined number of slits 10 are provided inside, and the slits 10
A vane 11 and a vane adjusting spring 13 are inserted into the inside of the.

A cylindrical portion 14 having a central axis is provided in the case 1 at a position eccentric to the rotation axis of the cam rotor 12. The outer ends of the plurality of vanes 11 are movably in contact with the outer circumference of the columnar portion 14 on the side opposite to the spring side. When the cam rotor 12 rotates in the direction of the arrow shown in FIG. 1, the vane adjusting spring 13
Due to the biasing force of the
It rotates around the cylindrical portion 14 while contacting the outer periphery of the. As a result, the oil taken into the pump chamber from the suction port 15 is sucked as the volume of the pump chamber increases, and then the oil is discharged from the discharge port 16 due to the reduction of the volume of the pump chamber.

Next, the operation will be described. When the driving force is transmitted to the drive shaft 3 of the cycloid pump 2, the drive shaft 3
The drive rotor 4 rotates with the rotation of the driven rotor 5 and the driven rotor 5 rotates with the rotation of the gear 18,
The drive shaft 17 of the vane pump 9 rotates via 19.

The pump chamber 20 of the cycloid pump 2 is
After the oil is filled from the suction port 6, the drive rotor 4
The pump volume increases with the rotation of the. When the drive rotor 4 and the driven rotor 5 eventually reach the upper part of the partition wall 8, the volume of the pump chamber 20 becomes maximum, and thereafter, the volume of the pump chamber 20 decreases, so that the oil is discharged from the discharge port 7. That is, as the drive rotor 4 and the driven rotor 5 rotate, the volume of the pump chamber 20 is repeatedly increased and decreased to suck and discharge oil.

When the drive shaft 17 of the vane pump 9 rotates at a low speed, the setting force of the vane adjusting spring 13 provided inside the slit 10 formed in the cam rotor 12 is applied to the vane 11.
The centrifugal force exerted on the cam rotor 1
2, the pump chamber 21 between the vane 11 and the column portion 14.
Is formed. After the pump chamber 21 is filled with oil at the suction port 15, the volume of the cam rotor 12 continuously changes as the cam rotor 12 rotates, and the oil is discharged from the discharge port 16.

When the rotation speed of the drive shaft 17 further increases,
As shown in FIG. 3, the vane 11 that has been in contact with the columnar portion 14 is centrifugal force, and the centrifugal force acting in the radially outward direction overcomes the biasing force of the vane adjusting spring 13 to cause the columnar portion 14 to move.
The tip is separated from the outer peripheral part of. As a result, the cam rotor 12
The difference between the maximum volume and the minimum volume of the pump chamber 21 formed by the column portion 14 becomes small, and the discharge amount decreases. As the number of rotations of the drive shaft 17 further increases, the number of vanes 11 that gradually separate from the columnar portion 14 gradually increases, so that the pump discharge amount decreases each time, and finally all the vanes 11 are columnar as shown in FIG. When it is separated from the outer wall of the portion 14, the pump chamber 21 cannot be formed. As a result, the vane pump 9 stops the suction and discharge of oil. Therefore, in this case, oil is discharged only from the cycloid pump 2 and the oil discharge from the vane pump 9 is stopped, so that excess pumping of oil is reduced and loss of drive energy is suppressed.

Next, the relationship between the pump rotation speed and the discharge pressure of the composite pump according to the first embodiment will be described in comparison with the conventional constant-rate pump. As shown in FIG. 4, the discharge pressure curve of the conventional metering pump (conventional example) is shown by a dotted line, and the discharge pressure curve according to the first embodiment of the present invention is shown by a solid line. With regard to the discharge pressure of the composite pump according to the first embodiment of the present invention, a sufficient discharge pressure is secured by the discharge amounts of both the cycloid pump 2 and the vane pump 9 in the pump low rotation range. From the low speed region to the medium speed region, the discharge amount of the vane pump 9 gradually decreases as the engine speed increases, so that the discharge pressure does not increase in proportion to the pump speed and draws a flat discharge curve. Further, in the subsequent high speed rotation range, the vane pump 9 stops the pumping action and does not discharge the oil, so that the discharge pressure increases in proportion to the pump rotation speed without making the hydraulic pressure higher than necessary. Therefore, in the low speed region, the region indicated by A is the discharge pressure increasing region due to the movement of the vane pump, and the region indicated by B is the oil surplus pumping restraining region.

(Second Embodiment) FIG. 5 shows a second embodiment of the present invention.
Shown in. The second embodiment shown in FIG. 5 is an embodiment in which the composite pump of the first embodiment is applied to an oil supply circuit for engine oil. The oil pan 51 is connected to the suction port 6 of the cycloid pump 2 and the suction port 15 of the vane pump 9 via an oil strainer 52. The discharge port 7 of the cycloid pump 2 and the discharge port 16 of the vane pump 9 are connected to the passages 53 and 54 at a merging portion 55, respectively.
It is connected to the engine lubrication part 57 via. The relief valve 58 provided in the passage 53 is a control valve that returns the oil to the oil pan 51 on the low pressure side through the return passage 60 when the amount of oil to the engine lubricating portion 57 becomes excessive. The check valve 22 provided in the passage 54 is a check valve that prevents the discharge oil of the cycloid pump 2 from flowing back to the vane pump 9 side when the operation of the vane pump 9 is stopped.

From the oil pan 51 to the oil strainer 52
The oil sucked in via the suction ports 6 and 15 enters the pump chambers of the cycloid pump 2 and the vane pump 9, respectively, and is discharged from the discharge ports 7 and 16. In this embodiment, the maximum discharge amount of the vane pump 9 is larger than that of the cycloid pump 2. The present invention does not specify the magnitude of the maximum discharge amount.

(Third Embodiment) A third embodiment of the present invention is shown in FIG.
Shown in. The third embodiment shown in FIG. 6 is an example in which the vane pump chamber 62 of the first vane pump is provided outside the cam rotor 12 and the vane pump chamber 61 of the second vane pump is provided inside the cam rotor 12. First vane pump and second
Both the vane pumps are housed in the pump case portion 26.

In the first vane pump, a predetermined number of outer slits 102 are formed on the outer wall of the cam rotor 12 connected to a drive shaft (not shown), and the first vanes 112 are inserted inside the outer slits 102. In the first vane pump chamber 62, the inner wall of the pump case portion 26 is formed at an eccentric position with respect to the central axis of the cam rotor 12. The first vane 112 inserted into the outer slit 102 has one end abutting the inner wall of the pump case portion 26 and the other end housed in the outer slit 102 even when the first vane 112 is in the most extended state, so that the first vane 112 is outside. The slit 102 is prevented from slipping out. Regarding the first vane 112 inserted into the outer slit 102 on the outer peripheral side of the cam rotor 12, the volume of the first vane pump chamber 62 formed by the cam rotor 12, the first vane 112, and the inner wall of the pump case portion 26 is equal to the volume of the cam rotor. Oil is discharged by repeating increase and decrease with the rotation of 12. That is, the oil taken from the suction port 24 is accelerated by increasing the volume of the pump chamber, and then the volume of the pump chamber is reduced to discharge the oil from the discharge port 25.

In the second vane pump, a predetermined number of inner slits 101 are formed on the inner wall of the cam rotor 12. Inside the inner slit 101, the vane adjusting spring 1
3 and the second vane 111 are inserted, and the second vane 111 is brought into close contact with the cylindrical portion 14 by the pressing force of the vane adjusting spring 13.

In the second embodiment, the second vane pump chamber 61 has the second vane 1 when the rotation speed increases.
Since 11 disengages the contact with the cylindrical portion 14, the oil discharge by the inner second pump is stopped in the high speed rotation range. Therefore, the relationship between the pump rotation speed and the oil discharge amount can have the same characteristics as those of the first embodiment.

(Fourth Embodiment) A fourth embodiment of the present invention is shown in FIG.
Shown in. In the fourth embodiment shown in FIG. 7, the first pump is shown in FIG.
It is a cycloid pump similar to the first embodiment shown in FIG.
A description of this cycloid pump portion is omitted, and FIG. 7 shows an electromagnetically controlled vane type pump which is the second pump.

In the vane pump of the first embodiment shown in FIG. 1 described above, the vane of the second pump was mechanically controlled, that is, centrifugal force control, but in this fourth embodiment, the contact of the vane with the cylindrical portion and its contact. This is an example in which release and release are controlled by an electromagnetic drive system.
In this fourth embodiment, the electromagnetic drive shaft 28 functions as a vane. The electromagnetic drive shaft 28 is controlled by the output of a control circuit that receives and outputs output signals of a hydraulic pressure sensor and an engine speed sensor. The electromagnetic drive shaft 28 is inserted into the slit 10, and performs electronic control so that the tip of the electromagnetic drive shaft 28 comes into contact with the columnar portion 14 when the pump is rotating at a low speed. When the pump rotational speed increases, the electric signal input to the coil 29 is changed, and the electromagnetic drive shaft 28 is moved to the cylindrical portion 14
The amount of oil discharge can be controlled by switching the magnitude of the urging force in the direction of contact with or the direction of separation. That is, it is possible to control the magnitude of the oil discharge amount by changing the distance between the tip of the electromagnetic drive shaft 28 that is in contact with the columnar portion 14 and the columnar portion 14. The second pump has a suction port 30 and a discharge port 31.

In the fourth embodiment, by controlling the position of the electromagnetic drive shaft 28 that acts as a vane, the discharge of the second pump can be turned on / off and the discharge amount can be linearly controlled. The first pump type applicable to this embodiment includes a gear pump, a vane type pump, and other pumps.

(Fifth Embodiment) FIG. 8 shows a fifth embodiment of the present invention.
Shown in. In the fifth embodiment shown in FIG. 8, the first pump is the first
Similar to the embodiment, only the second pump is shown in FIG. In the example shown in FIG. 8, magnetic force is used for vane control. The vane 11 is made to have magnetism of either N pole or S pole. A magnetic force generating portion 65 capable of changing the generated magnetic force and magnetism is formed on the other cylindrical portion 14.
When the discharge hydraulic pressure is increased, a magnetism opposite to the magnetism of the vane 11 is generated in the magnetic force generator 65, and the vane 11 is moved to the cylindrical portion 14.
Suction to close contact. This enables oil to be discharged from the second pump. When it is not necessary to increase the discharge hydraulic pressure, the vane 11 is separated from the columnar portion 14 by the repulsive force by making the magnetism of the vane 11 the same as the magnetism generated by the magnetic force generator 65. As a result, pumping by the pump chamber is disabled and oil discharge is stopped.

(Sixth Embodiment) A sixth embodiment of the present invention is shown in FIG.
Shown in. In the embodiment shown in FIG. 9, the fourth shown in FIG.
This is an example in which the oil pressure sensor 66 is provided in the oil passage of the embodiment, and the output of this oil pressure sensor is involved in the control of the vane of the second pump. For example, when the hydraulic pressure value detected by the hydraulic pressure sensor exceeds a desired hydraulic pressure value, the second pump is stopped by electromagnetically driving the vane 11 away from the columnar portion 14. With such a composite pump capable of feedback by the oil pressure sensor, it is possible to precisely control the oil discharge amount and the oil discharge pressure.

In the fifth embodiment shown in FIG. 8, it is also possible to carry out feedback control of the magnetic force generator by a hydraulic sensor as shown in FIG.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram showing a composite pump according to a first embodiment of the present invention.

2 is a vertical cross-sectional view of the embodiment shown in FIG.

FIG. 3 is a partial view showing a high speed rotation state of the second pump of the embodiment shown in FIG.

FIG. 4 is a characteristic diagram showing pump characteristics according to the first embodiment of the present invention.

FIG. 5 is an oil circuit diagram showing a second embodiment of the present invention.

FIG. 6 is a schematic configuration diagram of a composite pump according to a third embodiment of the present invention.

FIG. 7 is a partial configuration diagram showing a composite pump of a fourth embodiment of the present invention.

FIG. 8 is a partial configuration diagram of a composite pump of a fifth embodiment of the present invention.

FIG. 9 is a schematic configuration diagram of a composite pump according to a sixth embodiment of the present invention.

[Explanation of symbols]

1 compound pump 2 cycloid pump 3 drive axis 4 drive rotor 5 driven rotor 6 suction port 7 outlet 8 partitions 9 Vane pump (second pump) 10 slits 11 vanes 12 cam rotor 13 Vane adjustment spring 14 Column 17 Drive shaft 18, 19 gear 23 Check valve 26 Pump case part 28 Electromagnetic drive shaft 29 coils 60 Return passage 65 Magnetic force generator

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) F04C 2/344 331 F04C 2/344 331M 2/356 2/356 C 11/00 11/00 D 15/04 321 15/04 321G (72) Inventor Toshihiro Takahara 1-1 chome, Toyota-cho, Kariya city, Aichi F-term in Toyota Boshoku Co., Ltd. (reference) 3G013 BB02 BB18 BB19 BB32 EA02 3H040 AA03 BB01 BB13 CC09 DD02 DD07 DD09 DD15 DD21 DD26 DD32 DD37 DD40 3H041 AA02 BB04 CC20 DD02 DD05 DD07 DD10 DD11 DD38 3H044 AA02 BB03 BB05 CC19 DD01 DD05 DD06 DD08 DD11 DD14 DD19 DD28 3H071 AA03 BB02 BB13 BB14 CC15 CC37 DD06 DD32 DD35 DD42

Claims (7)

[Claims] 1. A composite pump in which a power hoop which rotates by a drive shaft of an internal combustion engine and a vane type pump which rotates by receiving a driving force of a power pump are arranged in parallel. 2. A check valve for allowing oil to flow only from the vane pump side to the power hoop side is provided in an oil passage connecting the discharge port of the power hoop and the discharge port of the vane pump. Claim 1 characterized by the above.
The described composite pump. 3. The composite pump according to claim 1, wherein the power hoop is a gear pump. 4. A first passage that is formed in a first passage that connects the suction port and the discharge port, and is formed in a second passage that bypasses the first passage and connects the suction port and the discharge port. A pump housing having a second pump chamber, a first driven rotor rotatably provided on the inner wall of the first pump chamber and having internal teeth, and a first drive rotor having external teeth meshing with the internal teeth, The first drive rotor is attached to rotate the first drive rotor by the driving force of the internal combustion engine.
A power pump having a pump shaft and performing a pumping action by meshing of the inner teeth and the outer teeth, a cam rotor rotatably provided on the second pump chamber inner wall, and eccentrically provided inside the cam rotor. A vane type pump having a cylindrical portion, a vane capable of reciprocating in a slit formed in the inner wall of the cam rotor, and a biasing means for biasing the tip of the vane in the direction of pressing the cylindrical portion. A composite pump characterized by 5. A pump case, a cam rotor provided at an eccentric position inside the pump case and rotating by receiving a driving force, and a plurality of first insertable insertable inserts into slits formed on the outside of the cam rotor. A first vane pump which sucks and discharges fluid by repeating expansion and contraction of the volume of the pump chamber as the cam rotor rotates while the tip of the first vane slides on the inner wall of the pump case, A columnar portion provided at an eccentric position inside the cam rotor, a plurality of second vanes capable of advancing and retracting in a slit formed inside the cam rotor, and a direction in which the tip end of the second vane is pressed against the columnar portion. An urging means for urging is provided, and while the tip of the second vane slides on the outer wall of the cylindrical portion, the volume of the pump chamber repeats expansion and contraction as the cam rotor rotates. Second composite pump having a vane pump for discharging the suction fluid. 6. The composite pump according to claim 4, wherein the vane position of the vane pump is controlled by an electromagnetic force of a coil portion arranged on the cam rotor side. 7. The composite pump according to claim 4, wherein the position of the vane of the vane pump is controlled by the magnetic force of a magnetic force generator arranged on the side of the column.