JP2008101561A - Control device for fluid pump - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a control device for a fluid pump, which can release a motor lock state. <P>SOLUTION: When the motor lock state is detected in starting of a fuel pump 11, an armature coil 21 is electrified in a first non-rotating pattern set in advance. Therefore, damaging of an armature coil of a specified phase by heat, caused by a continuous flow of an electric current in an armature coil, can be suppressed. The first non-rotating pattern is a pattern generating heat of a degree where the armature coil 21 does not generate heat excessively, so that the fuel pump 11 is heated without burning off the armature coil to release motor lock caused by freezing. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a control device for a fluid pump.

Conventionally, a brushless fuel pump for a vehicle using a brushless motor as a drive source is known (for example, see Patent Document 1). Here, in the brushless motor, the rotor is rotated by sequentially switching energization to the armature coils in accordance with the rotational position of the rotor.
Japanese Patent Laid-Open No. 11-270468

  When a vehicle equipped with a fuel pump is placed in a low-temperature environment, the shaft bearing portion may freeze to prevent the motor from rotating (hereinafter referred to as “motor lock state”). . In addition, foreign matters such as dust mixed in the fuel may be caught between the rotor and the stator or may be bitten by the impeller of the pump unit, and the motor may be locked.

  When the motor is locked, the rotational position of the rotor does not change. Therefore, if energization control is performed such that the rotor is rotated without the motor locked state being eliminated, energization to a predetermined phase coil is continued. If this energized state is continued, the amount of heat generated in a predetermined phase coil increases, and eventually the phase coil may be damaged by heat.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide a fluid pump control device capable of eliminating the motor lock state or suppressing the occurrence of the motor lock state.

  Hereinafter, means and the like effective for solving the above-described problems will be described while showing functions and effects as necessary.

  The invention according to claim 1 includes a stator having a multi-phase armature coil, and a rotor having a field pole disposed to face the stator, and energizes the armature coil of each phase. The present invention relates to a fluid pump control device that controls a brushless fluid pump that controls the brushless fluid pump that sucks fluid by the rotation of the rotor and sucks fluid by the rotation of the rotor. The first energization pattern for rotating the rotor by switching energization to the armature coils of each phase according to the rotational position of the rotor, and energization and de-energization in a manner that does not rotate the rotor. The armature coil is provided with an energization control means capable of energizing the armature coil in any one of the second energization patterns for switching between.

  In a fluid pump, the rotor rotation shaft bearing is frozen, or dust or other foreign matter contained in the fluid is caught between the rotor and the stator, etc., and the rotor is prevented from rotating (locked). State). In this case, if rotation control is performed such that the energization of the armature coils of each phase is switched according to the rotation position of the rotor, the rotor is locked and the rotation position does not change. It will continue to be done. Then, by continuing to energize the armature coil of a predetermined phase, the amount of heat generated by the armature coil of that phase increases, and the armature coil may eventually be damaged by heat.

  In this regard, in the present invention, it is possible to energize the armature coil for a predetermined period with the second energization pattern that switches between energization and non-energization without rotating the rotor. By switching between energization and non-energization of each phase armature coil in the second energization pattern, it is possible to suppress an increase in the amount of heat generated by the armature coil by continuing energization to the armature coil of a predetermined phase. . As a result, it is possible to prevent the armature coil from being damaged by heat.

  By energizing the armature coil with the second energization pattern for a predetermined period, the armature coil can generate a predetermined amount of heat while suppressing an increase in the amount of heat generation. For this reason, it is possible to warm the fluid pump, and as a result, it is possible to eliminate the locked state due to freezing or to prevent the locked state due to freezing.

  Further, by energizing a predetermined phase of the armature coil, the rotor is attracted to the stator side. The rotor slightly moves to the stator side due to a slight clearance generated in the bearing portion of the rotating shaft of the rotor. Therefore, the rotor can be minutely vibrated in the radial direction by switching between energization and non-energization of the armature coils of each phase in the second energization pattern. Foreign matter sandwiched between the rotor and the stator often exists in a state compressed in the radial direction, but the foreign matter is removed from between the rotor and the stator by vibrating the rotor in the radial direction. It becomes possible. As a result, it is possible to eliminate the locked state due to the foreign matter or to suppress the locked state due to the foreign matter.

  As described in claim 2, the second energization pattern may be a prescribed pattern that is defined in advance so that energization and non-energization are switched over time. Instead of switching energization according to the rotational position, it is possible to obtain an energization pattern that does not rotate the motor by switching energization with a prescribed pattern that is defined in advance as time passes.

  According to a third aspect of the present invention, the energization control unit energizes the armature coil with the second energization pattern for a predetermined period when the fluid pump is started. As a result, even when the fluid pump is in a locked state when the fluid pump is stopped, the locked state is released and the engine can be started well.

  The invention according to claim 4 is characterized in that the energization control means energizes the armature coil with the second energization pattern for a predetermined period immediately after the fluid pump is stopped.

  During the rotational driving of the fluid pump, the rotational energy of the rotor is high, so even if foreign matter such as dust is mixed in the fluid, the foreign matter is repelled by the rotor. Therefore, there is a low possibility that the fluid pump is locked due to dust being caught between the rotor and the stator during the rotational driving of the fluid pump. On the other hand, immediately after the fluid pump is stopped, the rotor stops, whereas the fluid flow remains due to inertia. For this reason, there is a higher probability that a foreign substance mixed in the fluid will be in a locked state by being sandwiched between the rotor and the stator, for example, while the fluid pump is being driven to rotate. In this regard, in the present invention, the armature coil is energized with the second energization pattern that switches between energization and non-energization immediately after the fluid pump is stopped. By switching between energization and non-energization, it is possible to generate minute vibrations in the rotor at a time when the probability of a locked state is high. As a result, it is possible to prevent the locked state from being caused by foreign matter being sandwiched between the rotor and the stator. Note that “immediately after stopping the fluid pump” refers to a time point when the rotor of the fluid pump is stopped but the fluid flow remains due to inertia.

  The invention according to claim 5 is characterized in that the energization control means energizes the armature coil with the second energization pattern for a predetermined period after a predetermined time has elapsed since the fluid pump was stopped. When the fluid pump is placed in a low-temperature environment after the fluid pump is stopped, the bearing portion of the rotating shaft of the rotor may freeze and enter a locked state. In this regard, the fluid pump can be warmed by performing energization with the second energization pattern for a predetermined period after a predetermined time has elapsed since the fluid pump was stopped. As a result, it is possible to prevent the bearing portion of the rotating shaft of the rotor from freezing, and to prevent the locked state from being frozen.

  The invention according to claim 6 is characterized in that the armature coil is energized for a predetermined period with the second energization pattern every time a predetermined time elapses after the fluid pump is stopped. By performing energization with the second energization pattern for a predetermined period each time a predetermined time elapses after the fluid pump is stopped, the fluid pump can be periodically warmed. As a result, even when the fluid pump is placed in a low temperature environment for a long period of time, it is possible to prevent the bearing portion of the rotor rotating shaft from freezing and to prevent the locked state from being frozen. It becomes.

  According to a seventh aspect of the invention, there is provided a temperature acquisition means for acquiring a temperature in the vicinity of the fluid pump, and the energization control means is configured such that the temperature acquired by the temperature acquisition means after the fluid pump is stopped is a predetermined temperature. In the following cases, the armature coil is energized for a predetermined period in the second energization pattern. Thereby, when the temperature in the vicinity of the fluid pump is equal to or lower than the predetermined temperature and there is a high possibility that the fluid pump is locked, the fluid pump can be warmed. As a result, it is possible to prevent the locked state from being frozen.

  According to an eighth aspect of the present invention, there is provided a lock state detecting means for detecting the lock state of the fluid pump, and the energization control means is provided on the condition that the fluid pump is detected to be in the lock state. The armature coil is energized for a predetermined period with an energization pattern. Thereby, since the locked state of the fluid pump can be detected, it is possible to perform energization with the second energization pattern at an appropriate time.

  In a ninth aspect of the invention, the lock detecting means determines that the fluid pump is in a locked state when the energized state of the armature coils of each phase continues for a predetermined time without switching. It is characterized by that. As described above, the energization of each phase armature coil is switched according to the rotational position of the rotor, whereby the rotor rotates. However, since the rotor does not rotate in the locked state, the predetermined energized state continues. Therefore, the state in which the rotor is not rotating, that is, the locked state, can be determined by detecting that the energized state of the armature coils of each phase continues for a predetermined time without switching.

  As the energization by the second energization pattern, as in the invention according to claim 10, during the energization period by the second energization pattern, only the specific two phases of the armature coil are energized and the other phases are de-energized. Alternatively, as in the eleventh aspect of the present invention, all phases of the armature coil may be energized simultaneously during the energization period of the second energization pattern. Thereby, cancellation | release of a locked state or generation | occurrence | production of a locked state can be suppressed. In particular, in the invention described in claim 11, since all phases are energized simultaneously, the entire fluid pump can be warmed substantially uniformly. This facilitates releasing the locked state due to freezing, and increases the effect of preventing the locked state from being frozen.

  The invention according to claim 12 is characterized in that the energization control means intermittently energizes the armature coil as the energization by the second energization pattern during the energization period by the second energization pattern. Yes. This makes it possible to continuously vibrate the rotor in the radial direction. As a result, it is possible to easily release the locked state due to the inclusion of foreign matter such as dust, and to increase the effect of suppressing the locked state due to the insertion of foreign matter.

  The invention according to claim 13 is characterized in that the energization control means switches energization to the armature coils of each phase at the natural frequency of the rotor. Thereby, the amplitude of the vibration of the rotor can be increased. As a result, it is possible to more easily release the locked state due to dust pinching and the like, and it is possible to further increase the effect of suppressing the locked state due to dust pinching and the like.

[First embodiment]
Hereinafter, an embodiment in which the present invention is applied to a fuel pump for a vehicle will be described with reference to the drawings.

  First, the overall configuration of the fuel pump will be described with reference to FIG. The fuel pump 11 is configured by incorporating a pump unit 13 and a brushless motor 14 in a cylindrical housing 12. The configuration of the pump unit 13 will be described. A pump chamber 17 is constituted by a pump casing 15 and a pump cover 16 fixed to one end of the cylindrical housing 12 by press-fitting, caulking or the like, and an impeller 18 is accommodated in the pump chamber 17. Has been. The impeller 18 is fitted on the shaft 24 of the brushless motor 14 and rotates together with the shaft 24.

  On the other hand, the brushless motor 14 is, for example, a three-phase full-wave drive type brushless motor, and is configured as follows. A cylindrical stator 19 is fitted and fixed in the cylindrical housing 12, and for example, six salient poles 20 are formed on the stator 19 as shown in FIG. These salient poles 20 are equipped with two U, V and W phase three-phase armature coils U21, V21 and W21 in the order of U phase, V phase and W phase. Coils are connected in series (see FIG. 3).

  A magnet rotor 23 is arranged on the inner peripheral side of the six-pole stator 19 configured as described above. The magnet rotor 23 includes a rotor core 25 fitted to the shaft 24 and, for example, eight field magnets 26 fixed to the outer periphery of the rotor core 25 by adhesion or the like. As shown in FIG. 2, the eight magnets 26 are arranged so that the N poles and the S poles are alternately arranged, thereby forming an eight pole magnet rotor 23.

  As shown in FIG. 1, one end of the shaft 24 of the magnet rotor 23 is rotatably supported by a bearing tube portion 28 at the center of the pump casing 15 via a bearing 27. The other end of the shaft 24 is rotatably supported by a bearing holder 30 fixed in the cylindrical housing 12 via a bearing 29. The bearing holder 30 is assembled with a drive control circuit 31 of a three-phase full-wave drive system. When the brushless motor 14 is driven, the drive control circuit 31 sequentially energizes the armature coils U21, V21 and W21 of each phase. Can be switched. A housing cover 33 having a discharge port 32 is fitted into the opening of the cylindrical housing 12 on the drive control circuit 31 side.

  When the impeller 18 of the pump unit 13 is rotationally driven by the brushless motor 14, the fuel in the fuel tank (not shown) is sucked into the pump chamber 17 from the suction port (not shown) of the pump cover 16, and the pump casing. It is discharged into the cylindrical housing 12 from 15 discharge ports (not shown). This fuel flows through a gap between the stator 19 and the magnet rotor 23, is discharged from a discharge port 32 of the housing cover 33 into a fuel pipe (not shown), and is sent to a fuel injection valve (not shown).

  As shown in FIG. 4, the three-phase armature coils U21, V21, and W21 are star-connected. The drive control circuit 31 includes a control unit 35 and a switching element unit 46 that switches energization to the armature coils U21, V21, and W21 of each phase based on the output of the control unit 35. The switching element unit 46 is composed of six MOSFETs (U1, U2, V1, V2, W1, W2). Each of these two pairs is connected in a bridge between the battery voltage (+ B) side and the ground side, and each pair of MOSFETs is connected to one end of each of the star-connected electronic coils U21, V21 and W21. The intermediate connection point is connected. Then, a battery voltage that is a drive voltage of the brushless motor 14 (applied voltage to the armature coils U21, V21, and W21 of each phase) is input to the control unit 35.

  The vehicle is provided with an ignition switch (hereinafter referred to as “IG switch”) 36 for detecting a request for starting / stopping the engine by the user, and the detection result of the engine start / stop request by the IG switch 36 is input to the control unit 35. Is done. The start and stop of the fuel pump 11 are linked with the start and stop of the engine. Therefore, the start and stop of the fuel pump 11 can also be estimated by the input from the IG switch 36. Further, a temperature detection unit 37 is provided in the vicinity of the fuel pump 11, and a detection result by the temperature detection unit 37 is input to the control unit 35.

  The drive control circuit 31 rotationally drives the brushless motor 14 by a two-phase energization method. At this time, the control unit 35 of the drive control circuit 31 detects the induced voltage generated in the armature coil 21 in the non-energized phase based on the neutral point voltage, and the rotational position of the magnet rotor 23 is determined based on the neutral point voltage. To detect. As shown in FIG. 5, the control unit 35 sequentially switches the upper and lower MOSFETs (U <b> 1 to W <b> 2) of each phase according to the rotational position of the magnet rotor 23. Then, the brushless motor 14 is rotationally driven by simultaneously energizing the armature coil 21 of two phases out of the three phases with the energization pattern shown in FIG. 6 (hereinafter referred to as “rotation pattern”).

  The controller 35 can energize the armature coil 21 in the first and second non-rotating patterns that are energization patterns that do not rotate the magnet rotor 23 in addition to energization in the rotation pattern shown in FIG. ing. The first and second non-rotating patterns do not switch the MOSFETs (U1 to W2) in accordance with the rotational position of the magnet rotor 23, but the upper and lower stages of each phase are energized in a preset pattern. The MOSFETs (U1 to W2) are sequentially switched.

  The energization in the first and second non-rotating patterns is executed by the control unit 35 for a predetermined period when the motor lock state is detected when the fuel pump 11 is started. Here, the motor lock state means that the bearing portion of the shaft 24 is frozen, or dust or the like in the fuel is sandwiched between the magnet rotor 23 and the stator 19 or bitten by the impeller 18. Therefore, the rotation of the brushless motor 14 is prevented.

  The detection of the motor lock state is performed as follows. As described above, when the brushless motor 14 is rotationally driven, the control unit 35 sequentially switches the MOSFETs (U1 to W2) of each phase according to the rotational position of the magnet rotor 23. However, since the rotational position of the magnet rotor 23 does not change when the motor is locked, a certain energized state (switching state) continues after the fuel pump 11 is started. The control unit 35 measures the duration of the switching state, and determines that the motor is locked when the duration is equal to or longer than a predetermined time.

  FIG. 7 shows the first non-rotation pattern of this embodiment, and FIG. 8 shows the second non-rotation pattern. As shown in FIGS. 7 and 8, in the first and second non-rotating patterns, only two specific phases among the three phases are energized, and the remaining one phase is continuously de-energized. Specifically, the U phase is energized in the positive direction for a predetermined period, and the V phase is energized in the negative direction during the period in which the U phase is energized in the positive direction. In addition, the W phase is not energized for the entire period. When energized in the first and second non-rotating patterns, the brushless motor 14 does not sequentially switch energization to the armature coils U21, V21, and W21 of each phase according to the rotational position of the magnet rotor 23. It is not rotated.

  In the first non-rotating pattern shown in FIG. 7, the U-phase and V-phase armature coils U21 and V21 are energized for a relatively long time so as not to overheat. Since energization is performed for a relatively long time, when the armature coil 21 is energized in the first non-rotating pattern, the armature coil 21 effectively generates heat.

  In the second non-rotating pattern shown in FIG. 8, the U-phase and V-phase armature coils U21 and V21 are intermittently energized with a relatively short period. While the two-phase armature coil 21 is energized, the magnet rotor 23 is attracted in a specific direction by a magnetic force by a minute clearance between the bearings 27 and 29 and the shaft 24. When the energization is stopped, the magnetic attraction is stopped, and the magnet rotor 23 returns to the original position. Therefore, when energization and de-energization are repeated in a short cycle as in the second non-rotating pattern, the magnet rotor 23 slightly vibrates in the radial direction. Therefore, when the armature coil 21 is energized in the second non-rotating pattern, dust or the like sandwiched between the magnet rotor 23 and the stator 19 or bitten by the impeller 18 is effectively removed. be able to. Note that the cycle of the energization / non-energization switching waveform in the second non-rotating pattern is set to be the natural frequency of the magnet rotor 23. For example, when the natural frequency of the magnet rotor 23 is 100 Hz, as shown in FIG. 8, the cycle of the switching waveform of energization / non-energization in the second non-rotation pattern is 10 msec.

  Next, a control procedure for releasing the motor lock state when the fuel pump 11 is started will be described. In this control, the armature coil 21 is heated by energizing the armature coil 21 in the first non-rotating pattern, and the motor lock state due to freezing is to be released. Further, by energizing the armature coil 21 in the second non-rotating pattern, the magnet rotor 23 and the impeller 18 are vibrated, and the motor locked state due to dust pinching or the like is to be released.

  FIG. 9 is a flowchart showing a control procedure for releasing the motor lock state when the fuel pump 11 is started. The routine shown in FIG. 9 is executed by the control unit 35 after the ON state of the IG switch 36 is detected.

  First, in step S101, the counter n is set to 0. Next, in step S102, the armature coil 21 is energized so that the brushless motor 14 is driven to rotate. That is, the MOSFETs (U1 to W2) of each phase are switched according to the rotational position of the magnet rotor 23, and the armature coils 21 of each phase are energized in a rotation pattern. In step S103, it is determined whether or not the motor is locked. The determination of the motor lock state is made based on whether or not a certain switching state continues for a predetermined time or more as described above.

  If the determination result of step S103 is NO, that is, if it is determined that the motor is not locked, this routine is terminated. After the end of this routine, the energization in the rotation pattern is continued and the fuel pump 11 is driven to rotate. Thereby, the fuel pump 11 sucks and discharges the fuel. On the other hand, if the decision result in the step 103 is YES, the process proceeds to a step S104, and the armature coil 21 is energized for a predetermined time with the first non-rotating pattern. As a result, the armature coil 21 of the energized phase generates heat.

  In step S104, after energizing for a predetermined time in the first non-rotating pattern, the process proceeds to step S105, and the armature coil 21 is energized to rotate the brushless motor 14 again. In other words, the armature coil 21 of each phase is energized in the rotation mode according to the rotational position of the magnet rotor 23. In step S106, it is determined whether or not the motor is locked.

  If the decision result in the step S106 is NO, this routine is finished. After the end of this routine, the energization in the rotation pattern is continued and the fuel pump 11 is driven to rotate. On the other hand, if the decision result in the step 106 is YES, the process proceeds to a step S107, and the armature coil 21 is energized for a predetermined time with the second non-rotating pattern. Thereby, the magnet rotor 23 vibrates.

  In step S108, the value of the counter n is incremented by 1, and in step S109, it is determined whether or not the value of the counter n is larger than the preset upper limit value nmax. If the decision result in the step S109 is NO, the process returns to the step S102, and the processes after the step S102 such as energization with the rotation pattern to the brushless motor 14 and the judgment of the motor lock state are executed again. On the other hand, if the determination result of step S109 is YES, the process proceeds to step S110. If the motor lock state is not resolved even if the processing from step S102 to step S107 is executed nmax times, there is a possibility that the brushless motor 14 has failed. Therefore, in step S110, the user is warned that there is a possibility that the brushless motor 14 has failed, for example, by lighting a lamp, and this routine is terminated.

  Next, a control procedure for preventing the fuel pump 11 from entering the motor lock state after the fuel pump 11 is stopped will be described. In this control, when a predetermined time has elapsed after the fuel pump 11 is stopped, the armature coil 21 is energized by energizing the armature coil 21 in the first non-rotating pattern, and the motor lock state due to freezing is prevented. To do.

  FIG. 10 is a flowchart showing a control procedure for preventing the fuel pump 11 from being in the motor lock state after the fuel pump 11 is stopped. The stop of the fuel pump 11 is detected by turning off the IG switch 36. The routine of FIG. 10 is executed by the control unit 35 after detecting the OFF of the IG switch 36.

  First, in step S201, the timer counter t is set to zero. In step S202, the value of the timer counter t is incremented by one. In step S203, it is determined whether or not the timer counter t is a set value T. The set value T is set in advance, for example, a value corresponding to 5 hours is set. This step S203 is a step of determining whether or not a preset time has elapsed after the IG switch 36 is turned off.

  If the determination result in step S203 is NO, the process returns to step S202, and the step of incrementing the timer counter t is repeated. On the other hand, if the decision result in the step S204 is YES, the process advances to a step S204, the armature coil 21 is energized for a predetermined time with the first non-rotating pattern, and this routine is ended.

  According to the embodiment described above in detail, the following excellent effects can be obtained.

  When the fuel pump 11 is in the motor lock state, the rotational position of the magnet rotor 23 does not change. Therefore, when energization is performed in a rotation pattern that switches energization to the armature coils of each phase according to the rotational position of the magnet rotor 23, energization to the armature coils 21 of a predetermined phase is continued. Then, by continuing to energize the armature coil 21 of a predetermined phase, the amount of heat generated by the armature coil 21 of that phase increases, and the armature coil 21 may eventually be damaged by heat.

  In this regard, in the present embodiment, when the motor lock state is detected at the time of starting the fuel pump 11, the energization to the armature coil 21 of each phase is not switched according to the rotational position of the magnet rotor 23. The armature coil 21 is energized with the first and second non-rotating patterns set in advance. In the first non-rotating pattern, the energizing time is set such that the armature coil 21 does not overheat, and in the second non-rotating pattern, the energizing pattern repeats energization and de-energization in a short cycle without continuing energization for a long period of time. Is set. Thereby, it can suppress that the emitted-heat amount of the armature coil 21 by energization to the armature coil 21 of a predetermined phase continues, and can suppress that the armature coil 21 is damaged by a heat | fever. It becomes possible.

  Then, by energizing the armature coil 21 for a predetermined period in the first non-rotating pattern, the armature coil can be effectively heated while suppressing overheating. For this reason, the fuel pump 11 can be effectively warmed, and as a result, the locked state due to freezing can be released.

  Further, by energizing a predetermined phase of the armature coil 21, the magnet rotor 23 is attracted to the stator 19 side. The magnet rotor 23 moves slightly toward the stator 19 due to a slight clearance generated between the shaft 24 and the bearings 27 and 29. Therefore, the magnet rotor 23 and the impeller 18 can be vibrated minutely in the radial direction by switching between energization and non-energization of the armature coils 21 of each phase. The dust sandwiched between the magnet rotor 23 and the stator 19 often exists in a state compressed in the radial direction. However, by vibrating the magnet rotor 23 in the radial direction, It becomes possible to remove dust from between.

  In particular, the magnet rotor 23 and the impeller 18 are continuously vibrated in the radial direction by energizing the armature coil 21 in a pattern that repeats energization and de-energization in a short cycle as in the second non-rotation pattern. Is possible. This facilitates the release of the motor lock state due to dust trapping or the like. In addition, the frequency of the energization / non-energization switching waveform of the second non-rotating pattern is set to be equal to the natural frequency of the magnet rotor 23. Thereby, since the magnet rotor 23 resonates, the amplitude of vibration can be increased, and it becomes easier to release the motor lock state. Note that the frequency of the switching waveform of energization / non-energization of the second non-rotating pattern may be set to be equal to a divisor of the natural frequency of the magnet rotor 23. Also by this, the rotor 23 resonates with the high-frequency component of the switching waveform of energization / non-energization of the second non-rotating pattern.

  In the present embodiment, the duration of the switching state is measured, and when the duration is a predetermined time or more, it is determined that the motor is locked. Thereby, it is possible to easily determine the motor lock state.

  In the present embodiment, if the motor lock state is not released even if energization for a predetermined time by the first and second non-rotation patterns is repeated nnax times, the user is warned by turning on the lamp or the like. As a result, the user can be informed of the possibility that a malfunction other than the motor lock state has occurred in the fuel pump.

  When the fuel pump 11 is placed in a low temperature environment after the fuel pump 11 is stopped, the bearing portion of the shaft 24 of the magnet rotor 23 may freeze and enter a motor lock state. In this regard, in the present embodiment, the armature coil 21 is energized for a predetermined time in the first non-rotating pattern after the predetermined time T has elapsed since the fuel pump 11 was stopped. Thereby, the fuel pump 11 can be warmed and it can suppress that the bearing part of the shaft 24 of the magnet rotor 23 freezes. As a result, it is possible to prevent the motor from being locked due to freezing.

[Second Embodiment]
11 and 12 are diagrams showing third and fourth non-rotating patterns, which are energization patterns that do not rotate the magnet rotor 23. FIG. The third non-rotation pattern shown in FIG. 11 is used instead of the first non-rotation pattern in the first embodiment, and the fourth non-rotation pattern shown in FIG. 12 is the second non-rotation pattern in the first embodiment. It is used instead.

  As shown in FIGS. 11 and 12, the third and fourth non-rotating patterns are patterns in which a specific two phases out of three phases are energized in the positive direction and the remaining one phase is energized in the negative direction. It is. Specifically, the U phase and the V phase are energized in the positive direction for a predetermined period, and the W phase is energized in the negative direction while the U phase and the V phase are energized. Since the third and fourth energization patterns do not sequentially switch the MOSFETs (U1 to W2) of each phase according to the rotational position of the magnet rotor 23, the brushless motor 14 is not driven to rotate. Even when energized in the third non-rotating pattern, the armature coil 21 generates heat effectively, as in the case of energizing in the first non-rotating pattern. Also, when energized in the fourth non-rotating pattern, the magnet rotor 23 vibrates in the radial direction, as in the case of energizing in the second non-rotating pattern. As a result, even when the third and fourth non-rotating patterns are used instead of the first and second non-rotating patterns, the same effects as those of the first embodiment are obtained.

  In particular, when energized in the third non-rotating pattern, all the three-phase armature coils 21 are energized, so that all the three-phase armature coils 21 can generate heat. For this reason, the fuel pump 11 can be efficiently warmed as a whole, and the frozen state can be eliminated more quickly.

[Third embodiment]
In the first embodiment, the armature coil 21 is energized in the first non-rotating pattern when a predetermined time has elapsed after the IG switch 36 is detected OFF. In the present embodiment, instead of the condition that the predetermined time has elapsed after the IG switch 36 is detected to be OFF, the first non-rotation is performed when the temperature detected by the temperature detecting means 37 is a predetermined temperature (eg, 0 ° C.) or less. The armature coil 21 is energized with a pattern.

  As a result, when the ambient temperature of the fuel pump 11 decreases and there is a high possibility that the motor will be locked due to freezing, the armature coil 21 can generate heat and the fuel pump 11 can be warmed. And it becomes possible to prevent that the bearing part of the shaft 24 freezes and falls into a motor lock state beforehand.

[Fourth embodiment]
In the first embodiment, the armature coil 21 is energized in the first non-rotating pattern when a predetermined time has elapsed after the IG switch 36 is detected OFF. On the other hand, in this embodiment, immediately after the OFF of the IG switch 36 is detected, the armature coil 21 is energized with the second non-rotating pattern.

  While the fuel pump 11 is driven to rotate, the magnet rotor 23 and the impeller 18 are rotating. While these are rotating, dust and the like mixed in the fuel is repelled by the rotation of the magnet rotor 23 and the impeller 18. Therefore, during the rotation of the magnet rotor 23 and the impeller 18, there is a low possibility that dust is caught between the magnet rotor 23 and the stator 19 or is bitten by the impeller 18 to enter the motor lock state. On the other hand, immediately after the fuel pump 11 is stopped, the rotation of the magnet rotor 23 and the impeller 18 is stopped, but the fuel flow remains due to inertia. Therefore, immediately after the fuel pump 11 is stopped, dust mixed in the fuel easily enters between the magnet rotor 23 and the stator 19, and there is a higher probability that the motor is locked than when the fuel pump 11 is rotationally driven.

  In this regard, in the present embodiment, the armature coil 21 is energized in the second non-rotating pattern immediately after the fuel pump 11 is stopped. For this reason, it is possible to generate minute vibrations in the magnet rotor 23 at a time when there is a high probability that the motor will be locked immediately after the fuel pump 11 is stopped. As a result, it is possible to reduce the possibility of dust being caught between the magnet rotor 23 and the stator 19 or being bitten by the impeller 18 to reach the motor lock state.

  In addition, this invention is not limited to the content of description of the said embodiment, For example, you may implement as follows.

  In the first embodiment, the motor lock state is detected when the fuel pump 11 is started. However, when the motor lock state is detected at a time other than the start time and the motor lock state is detected, the second non-rotating pattern is detected. May be energized. Thereby, even when a foreign object is bitten by the impeller 18 during operation and the motor is locked, the motor locked state can be released.

  In the first embodiment, the armature coil 21 is energized for a predetermined time in the first non-rotating pattern after the predetermined time T has elapsed since the fuel pump 11 was stopped. You may make it perform electricity supply by 1 non-rotation pattern. Thereby, even when a vehicle is parked for several days, it can suppress that it will be in a motor lock state by freezing. Further, the user may arbitrarily set the predetermined time T. According to this, when the user sets the time T corresponding to the next vehicle use, the fuel pump 11 can be warmed before using the vehicle, and the motor lock state due to freezing can be released in advance.

  In the first embodiment, the armature coil 21 is energized in the first non-rotating pattern for a predetermined time after the predetermined time T has elapsed since the fuel pump 11 was stopped. That is, the energization of the armature coil 21 in the first non-rotating pattern is finished after a predetermined time. However, the energization of the armature coil 21 may be terminated in the first non-rotating pattern when the temperature detected by the temperature detecting unit 37 is equal to or higher than a predetermined temperature. According to this, since the armature coil 21 can be energized until the fuel pump 11 is sufficiently warmed, the motor lock state due to freezing can be reliably released.

  It should be noted that means for detecting the voltage of the battery mounted on the vehicle is provided, and when the battery voltage is equal to or lower than a predetermined value, energization to the armature coil 21 is prohibited after the fuel pump 11 is stopped, or the energization time or frequency is May be reduced. As a result, it is possible to prevent the battery from rising due to energization when the vehicle is stopped.

The longitudinal cross-sectional view of the fuel pump which shows one Embodiment of this invention. AA sectional view taken on the line AA of FIG. The figure for demonstrating the winding method of the armature coil of each phase. The circuit diagram which shows the electric constitution of a brushless motor. The figure which shows the switching pattern of each MOSFET. The figure which shows the energization state of each phase in a rotation pattern. The figure which shows the energization state of each phase in a 1st non-rotation pattern. The figure which shows the energization state of each phase in a 2nd non-rotation pattern. The flowchart which shows the motor lock state cancellation | release routine at the time of fuel pump starting. The flowchart which shows the motor lock state prevention routine after a fuel pump stops. The figure which shows the electricity supply state of each phase in a 3rd non-rotation pattern. The figure which shows the electricity supply state of each phase in a 4th non-rotation pattern.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 11 ... Fuel pump, 12 ... Cylindrical housing, 13 ... Pump part, 14 ... Brushless motor, 15 ... Pump casing, 16 ... Pump cover, 17 ... Pump chamber, 18 ... Impeller, 19 ... Stator, 20 ... Salient pole, 21 ... Armature coil, 23 ... Magnet rotor, 24 ... Shaft, 25 ... Rotor core, 26 ... Magnet, 27, 29 ... Bearing, 28 ... Bearing cylinder, 30 ... Bearing holder, 31 ... Drive control circuit, 32 ... Discharge port, 33 ... housing cover, 35 ... control section.

Claims (13)

A stator having a multi-phase armature coil, and a rotor having a field pole disposed opposite to the stator, and the rotor rotates by sequentially switching energization to the armature coil of each phase. A control device for a fluid pump that controls a brushless fluid pump that sucks fluid by rotating the rotor and discharges the sucked fluid,
A first energization pattern for rotating the rotor by switching energization to the armature coils of each phase according to the rotational position of the rotor, and switching between energization and de-energization in a manner that does not rotate the rotor. An apparatus for controlling a fluid pump, comprising: energization control means capable of energizing the armature coil in any one of the second energization patterns.   2. The fluid pump control device according to claim 1, wherein the second energization pattern is a prescribed pattern that is defined in advance so that energization and non-energization are switched over time.   3. The fluid pump control device according to claim 1, wherein the energization control unit energizes the armature coil with the second energization pattern for a predetermined period when the fluid pump is started. 4.   4. The fluid pump according to claim 1, wherein the energization control unit energizes the armature coil with the second energization pattern for a predetermined period immediately after the fluid pump is stopped. 5. Control device.   The energization control unit energizes the armature coil with the second energization pattern for a predetermined period after a predetermined time has elapsed from the stop of the fluid pump. Fluid pump control device.   The energization control unit energizes the armature coil with the second energization pattern for a predetermined period every time a predetermined time elapses after the fluid pump is stopped. The control apparatus of the fluid pump as described. Having a temperature acquisition means for acquiring a temperature in the vicinity of the fluid pump;
The energization control unit energizes the armature coil with the second energization pattern for a predetermined period when the temperature acquired by the temperature acquisition unit is equal to or lower than a predetermined temperature after the fluid pump is stopped. The control apparatus of the fluid pump in any one of Claims 1-6. A lock state detecting means for detecting a lock state of the fluid pump;
8. The energization control unit energizes the armature coil with the second energization pattern for a predetermined period on condition that the fluid pump is detected to be in a locked state. The control apparatus of the fluid pump in any one.   The said lock | rock detection means determines with the said fluid pump being a lock | rock state, when the energization state to the armature coil of each said phase continues for a predetermined time, without switching. The control apparatus of the fluid pump as described.   In the energization period according to the second energization pattern, the energization control means energizes only two specific phases of the armature coil and de-energizes the other phases as energization according to the second energization pattern. The control apparatus of the fluid pump in any one of Claims 1-9.   The energization control unit energizes all phases of the armature coil simultaneously as energization by the second energization pattern during the energization period by the second energization pattern. The control apparatus of the fluid pump described in 1.   The energization control unit intermittently energizes the armature coil as energization by the second energization pattern during the energization period by the second energization pattern. The control apparatus of the fluid pump as described.   13. The fluid pump control device according to claim 12, wherein the energization control unit switches energization to the armature coils of each phase at a natural frequency of the rotor.

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