JP2012241593A - Electric gear pump - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electric gear pump of simple structure that can compensate for leakage variation in the gear pump and improve accuracy of flow rate control.SOLUTION: A rotating speed measured by a rotating speed detecting means 511 and a flow rate measured by a flow rate detecting means 531 are input (S4). A new relation between a control rotating speed and a flow rate is formed by a characteristic table 601 based on a relation between the measured rotation speed and flow rate (S5). An intersection of an approximate line indicating the new relation and a flow rate standard 611 is referred to, a control rotating speed to satisfy the flow rate standard 611 is extracted (S6), and a control rotating speed for correction is specified (S7). The control rotating speed for correction is then output to a rotating speed correction means 503 to perform alteration and memorization in the rotating speed correction means 503 (S8).

Description

  The present invention relates to an electric gear pump that controls a flow rate.

  Conventionally, an electric pump that controls the rotational speed of a trochoid gear pump using a brushless DC motor as a drive source is known.

  This electric pump includes a first rotor position detecting means for detecting the rotational position of the rotor based on a detection result by the speed electromotive force detecting means for detecting a speed electromotive force induced in the exciting coil, and a magnetic field from the magnet of the rotating shaft. And a second rotor position detecting means for detecting the rotational position of the rotor based on the detection result by the magnetic field detection unit for detecting the control, and the control based on the rotational position from the second rotor position detecting means is used depending on the temperature condition. Yes.

  Such a gear pump has a manufacturing variation in the clearance, which causes a leakage flow rate.

  For this reason, it is set so that the rotational speed is controlled quickly according to the gear pump with the largest leakage flow rate so that the desired flow rate can be maintained even with the gear pump with the largest leakage flow rate.

  That is, FIG. 6 is a diagram showing the control rotation speed with respect to the oil temperature. The control characteristic 801 for the product with the largest leakage flow rate is a solid line in FIG. This is indicated by a broken line in FIG.

  As described above, the best product can maintain the desired flow rate even if the control rotation speed for the oil temperature is low because the leak flow rate is small. However, for the product with a high leak flow rate, the control rotation for the oil temperature is possible. If the number is not set high, the desired flow rate cannot be maintained.

  For this reason, in this electric pump control device, the control characteristic 801 indicated by the solid line in FIG. 6 is uniformly set, and a gear pump having a relatively large clearance and a large leakage flow rate is assembled. Is also configured to maintain a desired flow rate.

JP 2008-086117 A

  However, in such a conventional electric pump, even when a gear pump with the smallest leakage flow rate is assembled, control is performed according to the control characteristic 801 when a gear pump with a large leakage flow rate is assembled. For this reason, the power consumption increases more than necessary.

  In order to solve this problem, a method of directly detecting the flow rate and correcting the rotation speed each time can be considered. However, in this case, the control process becomes complicated.

  The present invention has been made in view of such a conventional problem, and provides an electric gear pump that can compensate for the leakage variation of the gear pump and improve the flow rate control accuracy with a simple configuration. Objective.

  In order to solve the above-mentioned problem, the electric gear pump according to claim 1 of the present invention is an electric gear pump that controls the flow rate of oil by rotating the gear pump on a rotating shaft, and includes an oil temperature and Based on the inspection result of examining the relationship of the control flow rate to the rotation speed of the rotating shaft at the oil temperature and the flow rate standard in which the required flow rate to the oil temperature is determined, the relationship of the control rotation speed to the oil temperature is obtained, Control rotation speed characteristics determined based on this relationship were individually set.

  That is, when shipping inspection of the electric gear pump is performed, the oil temperature is measured, and the gear pump is operated by rotating the rotating shaft at a predetermined rotation speed at the oil temperature. And the rotational speed of the said rotating shaft and the control flow volume controlled by the said gear pump in this rotational speed are measured, and it is set as a test result.

  At this time, the required flow rate required for the oil temperature is determined as a flow rate standard according to specifications, etc., and a relationship between the flow rate standard and the inspection result is required, and a control determined based on this relationship. The rotational speed characteristics are individually set for the electric gear pump.

  More specifically, the rotational speed of the rotary shaft of the gear pump is proportional to the control flow rate controlled by the gear pump, and the rotational speed and the control flow rate are formed in the electric gear pump to be inspected. The NQ characteristic can be grasped from the inspection result.

  The required flow rate required at the oil temperature, which is the inspection condition at this time, is determined by the flow rate standard, and the rotational speed at which this required flow rate can be obtained can be obtained from the NQ characteristic.

  Further, the required flow rate with respect to the oil temperature is determined in advance as the flow rate standard, and the rotation speed for obtaining this required flow rate can be obtained from the NQ characteristics, and the rotation speed corresponding to the oil temperature is controlled. It is calculated | required as a rotational speed characteristic, and this control rotational speed characteristic is individually set to the said electric gear pump.

  In this way, the control rotational speed characteristics corresponding to the electric gear pump are individually set for the electric gear pump.

  In the electric gear pump according to claim 2, the control rotational speed characteristic is obtained based on a diagram formed by measuring a plurality of the control flow rates with respect to the rotational speed and the flow rate standard.

  That is, a plurality of control flow rates with respect to the rotation speed are measured to form a diagram, and the control rotation speed characteristic is obtained based on the diagram and the flow rate standard.

  For this reason, compared with the case where the relationship between the rotational speed and the control flow rate is measured at only one point and used as an inspection result, the NQ characteristic is obtained more accurately.

  As described above, in the electric gear pump according to the first aspect of the present invention, the control rotational speed characteristics corresponding to the electric gear pump are individually set for the electric gear pump. Optimal control corresponding to the clearance can be performed for each electric gear pump.

  For this reason, the control amount can be increased as much as necessary according to the leakage amount and the gear pump with a low leakage flow amount as compared with the conventional case where the control characteristics assuming a gear pump with a large leakage flow rate are uniformly set. In the case where is assembled, control suitable for the gear pump can be performed, and power consumption can be suppressed.

  Further, the cost can be reduced as compared with the case where the processing accuracy of the gear pump is required to suppress the leakage flow rate.

  Therefore, the leakage variation of the gear pump can be compensated with a simple configuration, and the flow control accuracy can be improved.

  In the electric gear pump according to claim 2, the NQ characteristic is obtained more accurately than in the case where the relationship between the rotational speed and the control flow rate is measured at only one point and used as an inspection result. be able to. Thereby, the further improvement of a control characteristic can be aimed at.

It is sectional drawing which shows one embodiment of this invention. It is a disassembled perspective view which shows the embodiment. It is a block diagram for demonstrating the embodiment. It is a flowchart which shows the procedure for the embodiment. (A) is a figure which shows the relationship between oil temperature and flow volume, (b) is a figure which shows the relationship between control rotation speed and flow volume, (c) is a figure which shows oil temperature and control rotation speed. It is a figure which shows the relationship of the control rotation speed with respect to oil temperature.

  Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

  FIG. 1 is a diagram showing an electric gear pump 1 according to the present embodiment. The electric gear pump 1 supplies oil for cooling a motor or an automatic transmission 2 such as an AT or CVT of an automobile. The hydraulic pressure that is attached to the cylinder and decreases during idle stop is maintained at a predetermined pressure (see FIG. 1).

  That is, a hydraulic circuit is formed in the automatic transmission 2, and a hydraulic path 12 for forming the hydraulic circuit is formed in the casing 11 of the automatic transmission 2. A mounting hole 14 for mounting the electric gear pump 1 is opened on the outer surface 13 of the casing 11 so that the front end portion of the electric gear pump 1 is inserted into the mounting hole 14. It is configured.

  Oil 21 used for control of the automatic transmission 2 circulates in the hydraulic path 12, and a back surface 22 of the mounting hole 14 has a communication path 23 communicating with an oil storage portion (not shown), and an additional pressure. An output path 24 for outputting the pressurized oil 21 is opened.

  FIG. 2 is an exploded perspective view showing the electric gear pump 1. The electric gear pump 1 includes a pump component 31 that constitutes a trochoid gear pump and a motor configuration that drives the pump component 31. And a motor drive controller 33 for controlling the motor component 32. The pump component 31, the motor component 32, and the motor drive controller 33 are arranged in the extending direction of the rotating shaft 34 that constitutes the motor component 32, and extend from the motor component 32. As shown in FIG. 1, the rotating shaft 34 is configured to be connected to the pump component 31 in the assembled state.

  The electric gear pump 1 includes a cylindrical case 41 constituting an outer peripheral portion, and the pump component 31 and the motor component 32 are fitted inside the case 41. In this internal fitting state, the outer peripheral surface of the pump component 31 and the outer peripheral surface of the motor component 32 are configured to contact the inner surface 42 of the case 41, and in this surface contact state, the pump The component 31 and the motor component 32 are configured to be positioned.

  A case flange portion 51 that extends outward is integrally formed at the base end of the case 41, and the electric gear pump 1 includes the case flange portion 51 as shown in FIGS. 1 and 2. The distal end side constitutes an insertion region to be inserted into the mounting hole 14 provided in the casing 11, and the proximal end side from the case flange portion 51 is configured to form a protruding region protruding from the casing 11. Yes.

  In a state where the electric gear pump 1 is mounted in the mounting hole 14, the case flange portion 51 is configured to contact the outer surface 13 of the casing 11, and the case flange portion 51 causes the electric motor pump 1 to be in contact with the outer surface 13. The gear pump 1 is configured to be fixed to the casing 11.

  The pump component 31 and the motor component 32 are arranged on the distal end side of the case 41 with respect to the case flange portion 51 constituting the insertion region, and the mounting state shown in FIG. , The front end surface of the pump component 31 protruding from the case 41 is configured to face the back surface 22 of the mounting hole 14.

  As shown in FIGS. 1 and 2, the pump component 31 includes a pump base 71 that forms a distal end side, and a pump housing 72 that is disposed on the proximal end side of the pump base 71, An O-ring 73 is disposed between the pump housing 72 and the pump base 71. As shown in FIG. 1, a circular projecting portion 74 that is inserted into the circular hole 62 of the case 41 and projects to the outside is integrally formed on the front end surface of the pump base 71. In the state where the outer peripheral portion of the protruding portion 74 is supported by the bent portion 61 at the tip of the case 41, the protrusion 74 is prevented from coming off to the tip side.

  One end portion of a pin 91 is inserted into the base end surface of the pump base 71, and the other end portion of the pin 91 is placed on the front end surface of the pump housing 72 arranged to face the pump base 71. Has been inserted. Accordingly, the pump housing 72 is positioned with respect to the pump base 71. In this state, the pump housing 72 is press-fitted and fixed to the case 41, and the outer peripheral surface of the pump base 71 is The case 41 is fixed in close contact with the inner surface 42.

  As shown in FIG. 1, the central portion of the pump housing 72 is immersed, and a rotor accommodating portion 101 is formed between the pump housing 72 and the pump base 71. A pump rotor outer 102 is rotatably accommodated in the rotor accommodating portion 101, and a pump rotor inner 103 is rotatably accommodated in the pump rotor outer 102.

  A suction port 111 and a discharge port 112 provided in the pump base 71 communicate with the rotor accommodating portion 101, and both ports 111, 112 are opened at the end surface of the projecting portion 74 of the pump base 71. Is configured to do.

  The suction port 111 is configured to be connected to the communication path 23 provided in the inner surface 22 of the mounting hole 14 in a state where the electric gear pump 1 is mounted in the mounting hole 14. The discharge port 112 is configured to be connected to the output path 24 through an O-ring 121.

  As a result, the pump rotor outer 102 rotates as the pump rotor inner 103 rotates, so that the oil sucked from the communication passage 23 through the suction port 111 is pressurized, and the discharge port 112 A trochoid pump that outputs to the output path 24 is formed.

  On the base end side of the trochoid pump, as shown in FIG. 1, a direct current motor constituted by the motor constituting portion 32 is disposed. The motor includes a motor case 201 that forms an outer peripheral portion, and the outer peripheral surface of the motor case 201 is fixed in a state of being in close contact with the inner side surface 42 of the case 41.

  A coil 212 around which a motor winding 211 is wound is fitted inside the motor case 201, and a stator 213 excited by the coil is held in the coil 212. A motor rotor core 214 is rotatably accommodated inside the stator 213, and a magnet 215 is provided on the outer peripheral surface of the motor rotor core 214. The rotation shaft 34 is inserted into the motor rotor core 214, and the rotation shaft 34 is fixed in a state of penetrating the motor rotor core 214.

  The other end portion of the rotating shaft 34 extends toward the front end side, and the rotating shaft 34 is inserted through the center hole 222 of the pump housing 72 through the oil seal 221 to be inside the rotor accommodating portion 101. It is comprised so that it may protrude. A flat surface 223 is formed on the peripheral surface of the rotating shaft 34 protruding from the rotor accommodating portion 101, and a rotor connecting portion 224 having a D-shaped cross section is formed. This rotor connecting portion 224 is inserted into the D-shaped hole 225 of the pump rotor inner 103 accommodated in the rotor accommodating portion 101, and then freely rotatable into the counterbore hole 227 of the pump base 71 via the tip side bearing. Supported in a contained state.

  The motor drive control unit 33 is disposed on the base end side of the motor configured by the motor configuration unit 32, and the motor drive control unit 33 is connected to the base end portion of the motor configuration unit 32. Insulator 301 is provided (see FIG. 2).

  The insulator 301 is made of synthetic resin, and is integrally formed with a motor connecting portion 311 that is inserted into the base end portion of the motor case 201 of the motor constituting portion 32 and connected in an internally fitted state. One end portion of the rotating shaft 34 is rotatably supported by the motor connecting portion 311 via a base end side bearing 314.

  Bus bars 321,... For relaying energization to the motor winding 211 are insert-molded in the motor connection portion 311, and the bus bars 321,. The motor winding 211 is electrically connected.

  In addition, a connector portion 322 that protrudes upward and has a harness connection hole 324 opened to the side is integrally formed on the side edge portion of the motor connection portion 311, and is formed on the back surface of the connector portion 322. The connection terminals 323 and 323 that are electrically connected to the harness are insert-molded.

  A plurality of support columns 333,... Are erected on the end surface of the motor connection unit 311, and a control board 334 is supported by the support columns 333,. An electronic circuit is formed on the control board 334, and the bus bar 321 is based on a signal input from the connector unit 322 in a state where the harness extended from an external device is connected to the connector unit 322. ,... Is configured to control the motor drive by controlling the output signal to.

  The motor drive control unit 33 includes a container-like controller cover 331 attached to the base end portion of the case 41, and the control board 334 supported by the motor connection unit 311 is configured by the controller cover 331. It is comprised so that it may be covered with.

  The controller cover 331 is made of aluminum, and a plurality of cooling fins 341,... For releasing heat generated inside to the outside are provided on the outer surface of the controller cover 331.

  An engagement recess 351 is formed in the base end portion of the connector portion 322 of the insulator 301, and the end portion side of the engagement recess 351 is slightly lower than the general portion of the connector portion 322 base end. A step portion 352 is formed. An extension piece 353 on one end side of the controller cover 331 that overlaps with the base end portion of the connector portion 322 is configured to extend on the stepped portion 352, and at the tip of the extension piece 353. The engaging convex portion 354 that engages with the engaging concave portion 351 is bent.

  As a result, the meshing structure in which the engagement convex portion 354 of the controller cover 331 is engaged with the engagement concave portion 351 of the connector portion 322 is engaged with the engagement convex portion 354 and the engagement concave portion. 351, a sealant is applied to a joint portion between the engagement recess 351 and the engagement projection 354 so that the engagement projection 354 and the engagement recess 351 are engaged with each other at the time of assembly. It is configured.

  Further, on the other end side of the controller cover 331, a cover flange portion 371 extending in a lateral direction from a portion externally fitted to the motor case 201 in a mounted state corresponds to the case flange portion 51. The cover flange portion 371 and the case flange portion 51 are in contact with each other and the outer fitting portion that is externally fitted to the motor case 201 is applied with a sealant during assembly. ing.

  A bolt insertion hole 381 is formed in the cover flange portion 371 and the case flange portion 51 that is in contact with the cover flange portion 371, and a collar 382 is fitted in the bolt insertion hole 381.

  As a result, as shown in FIG. 1, the bolt 391 inserted through the collar 382 in the bolt insertion hole 381 in a state where the case flange portion 51 is in contact with the outer surface 13 of the casing 11 at the time of mounting. The electric gear pump 1 can be fixed to the casing 11 by being screwed into a screw hole 392 formed in the casing 11.

  When the electric gear pump 1 is manufactured and shipped, a shipping inspection is performed, and a block diagram when the shipping inspection is performed is shown in FIG.

  That is, at the time of shipping inspection, the electric gear pump 1 is set in the inspection device, the oil temperature detecting means 501 coming from the oil temperature sensor for detecting the oil temperature of the oil used in the inspection device, and the oil temperature An external controller 502 configured by, for example, ATCU, which outputs an oil temperature signal from the detection unit 501 is provided. The external controller 502 outputs a control signal composed of, for example, a CAN communication signal or a PWM signal to the rotational speed correction means 503 configured by the controller of the motor drive control unit 33 in the electric gear pump 1, and The rotary shaft 34 of the electric gear pump 1 is controlled to rotate.

  The rotation speed correction unit 503 is configured to output a drive signal corresponding to the control signal to the motor 512 that is configured by the motor configuration unit 32 via the rotation speed detection unit 511, and the motor configuration unit The gear pump 513 which the pump structure part 31 comprises by the said 32 rotating shaft 34 is comprised so that it can operate | move.

  The rotational speed detection means 511 is configured to acquire a speed signal of motor rotation by obtaining an induced voltage generated during motor control, and is configured to output the acquired speed signal to the shipping inspection means 521. Yes.

  The flow rate of oil discharged from the gear pump 513 is configured to be detected by a flow rate detection unit 531 configured by a flow rate sensor, and the flow rate detected by the flow rate detection unit 531 is output to the shipping inspection unit 521. Is configured to do.

  The shipment inspection unit 521 is configured to output a signal to the rotation speed correction unit 503, and the rotation speed correction unit 503 is configured based on a signal from the shipment inspection unit 521, for example, an internal memory. It is configured to be able to perform operations such as changing the stored contents.

  The present embodiment according to the above configuration will be described with reference to the flowchart shown in FIG.

  In the electric gear pump 1 of the present embodiment, as shown in FIG. 5 (a), the supply flow rate of oil corresponding to the oil temperature to be flow controlled is determined by the specification as the flow rate standard characteristic 600. It is necessary to satisfy the specifications.

  That is, FIG. 4 shows the procedure of the shipping inspection. When the shipping inspection is started, the current oil temperature is detected by the oil temperature detecting means 501 (S1). Here, in the present embodiment, a case where the oil temperature is 40 ° C. will be described as an example. An oil temperature signal indicating the oil temperature (40 ° C.) is output to the external controller 502. At this time, the external controller 502 stores a characteristic MAP indicating the relationship between the oil temperature and the command DUTY, and the characteristic is fixed.

  Then, the external controller 502 that has received the oil temperature signal refers to the characteristic MAP, converts the oil temperature indicated by the oil temperature signal into a command DUTY (S2), and determines the command DUTY at the oil temperature. At the same time, a command DUTY signal corresponding to the command DUTY is output to the rotational speed correction means 503 together with the oil temperature signal. Then, the rotational speed correcting means 503 stores the command DUTY indicated by this signal in a memory (S3), and sends a drive signal corresponding to the command DUTY signal to the motor 512 via the rotational speed detecting means 511. To output the gear pump 513.

  At this time, the shipping inspection means 521 receives the rotational speed signal of the rotary shaft 34 of the gear pump 513 from the rotational speed detection means 511, calculates the rotational speed per predetermined time indicated by the signal, and The flow rate acquired from the flow rate detection means 531 is input, and the relationship between the rotation speed and the flow rate is measured (S4). It is assumed that the oil temperature (40 ° C.) detected by the oil temperature detection unit is also input to the shipping inspection unit 521 via the rotation speed correction unit 503.

  At this time, a shipping inspection MAP is stored in the shipping inspection means 521 in advance, and the shipping inspection MAP is controlled at a predetermined rotational speed as shown in FIG. 5 (b). The characteristic table 601 indicates the relationship between the flow rate and the flow rate (FIG. 5B shows the characteristic table when the oil temperature is 40 ° C.). The characteristics of the control rotation speed and the flow rate are constituted by a substantially linear approximate line, and the best product property 602 that is the gear pump 513 having the smallest leakage flow rate and the worst case that is the gear pump 513 having the largest leakage flow rate. The product characteristic 603 is constituted by a line that is substantially translated with a certain width.

  In each characteristic table 601 prepared for each oil temperature in the shipping inspection MAP, a flow standard 611 corresponding to the corresponding oil temperature is set (in FIG. 6B, the oil temperature is 40 ° C. The flow rate standard 611 indicates a flow rate determined by, for example, specifications required at the oil temperature (40 ° C.).

  Here, the shipment inspection unit 521 is configured to calculate the control rotation number in the characteristic table 601 corresponding to the oil temperature based on the relationship between the rotation number and the flow rate acquired from the rotation speed detection unit 511 and the flow rate detection unit 531. A new relationship with the flow rate is created (S5).

  For example, if the control rotation speed and flow rate are measured at two points and plotted to create a diagram, a desired approximate line connecting these two points can be obtained as the characteristic 604.

  Next, with reference to the intersection of the characteristic 604 composed of the approximate line and the flow rate standard 611, a control rotation number that satisfies the flow rate standard 611 is extracted (S6), and the correction control rotation number n is specified (S7). ).

  Then, the specified correction control rotational speed n is output to the rotational speed correcting means 503, and the rotational speed correcting means 503 changes and stores it (S8).

  More specifically, as shown in FIG. 5C, the rotational speed correction means 503 stores in advance a control MAP 621 that indicates the relationship between the oil temperature and the control rotational speed, and the oil of the control MAP 621 is stored. The characteristics of the temperature and the control rotational speed are also constituted by a substantially linear approximate line. The characteristic 622 of the best product that is the gear pump 513 having the smallest leakage flow rate and the characteristic 623 of the worst product that is the gear pump 513 having the largest leakage flow rate are diagrams that are slid in parallel with a certain width. It is configured.

  Therefore, if the correction control rotational speed n from the shipping inspection means 521 is plotted at one point at the corresponding position of the oil temperature (40 ° C.) on the control MAP 621, any of the characteristics of the oil temperature and the control rotational speed can be obtained. A control rotational speed characteristic 624 finally used for control can be formed by an approximate line passing through one point, and this can be updated and stored in the memory as a control rotational speed characteristic 624 used for controlling the electric gear pump 1. it can.

  This makes it possible to optimize the control rotation speed with respect to the oil temperature change only by changing the software.

  Thus, in the shipping inspection, the control rotational speed characteristic 624 corresponding to the electric gear pump 1 to be inspected can be individually set and stored for the electric gear pump 1, so that the gear pump 513 is stored. Optimum control according to the clearance can be performed for each electric gear pump 1.

  For this reason, the control characteristic assuming the gear pump 513 with a large leakage flow rate increases the control amount as necessary according to the leakage amount as compared with the conventional configuration in which all the electric gear pumps 1 are uniformly set. In addition, when the gear pump 513 having a small leakage flow rate is assembled, control suitable for the gear pump 513 can be performed, so that power consumption can be suppressed.

  Further, the cost can be reduced as compared with the case where the processing accuracy of the gear pump 513 is required to suppress the leakage flow rate.

  Therefore, the leakage variation of the gear pump 513 can be compensated with a simple configuration, and the flow control accuracy can be improved.

  In the present embodiment, the flow rate with respect to the control rotational speed is measured at two points to form a diagram (604), and the control rotational speed characteristic is obtained based on the diagram and the flow rate standard 611. It was.

  For this reason, the characteristic 604 (NQ characteristic) of the control rotation speed and the flow rate is obtained more accurately as compared with the case where the relationship between the control rotation speed and the flow rate is measured at one point and used as the inspection result. be able to.

  Thereby, the further improvement of a control characteristic can be aimed at.

1 Electric gear pump 31 Pump component 34 Rotating shaft

Claims (2)

An electric gear pump that controls the flow rate of oil by rotating a gear pump on a rotating shaft,
The relationship between the control rotation speed and the oil temperature based on the inspection result obtained by examining the relationship between the oil temperature and the control flow rate with respect to the rotation speed of the rotating shaft at the oil temperature and the flow rate standard in which the required flow rate with respect to the oil temperature is determined And a control rotational speed characteristic determined based on this relationship is individually set.   2. The electric gear pump according to claim 1, wherein the control rotational speed characteristic is obtained based on a diagram formed by measuring a plurality of the control flow rates with respect to the rotational speed and the flow rate standard.

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