JP5886175B2 - Engine start control device for fluid pressure assist vehicle - Google Patents

Description

  The present invention relates to an engine start control device for a fluid pressure assist vehicle.

  Conventionally, as in the technique described in Patent Document 1, a hydraulic pump / motor and an accumulator connected to an engine mounted on a vehicle are provided, and the hydraulic pump / motor operates as a pump driven by the engine when the vehicle is decelerated. The fluid pressure is accumulated in the accumulator to regenerate deceleration energy, while the vehicle is starting or accelerating, the fluid pressure pump / motor is operated as a motor to assist the engine drive with the fluid pressure accumulated in the accumulator. Vehicles equipped with an assist mechanism are well known.

  Further, in the technique described in Patent Document 2, a fluid pressure pump / motor and an accumulator connected to the engine via a clutch are provided, and the fluid pressure pump / motor is driven by the rotation of the axle to operate as a pump to thereby reduce the discharge pressure. The accumulator accumulates pressure, the clutch is engaged when the engine is started, the fluid pressure pump / motor is connected to the engine, and the fluid pressure accumulated in the accumulator is supplied to the fluid pressure pump / motor to operate as a motor. An engine start control device for starting the engine is proposed.

JP-A-7-137558 JP 2006-249990 A

  The engine is generally started with an electric starter that uses a battery as a power source. However, since the output torque is small, it is used in combination with a reduction gear mechanism, and as a result, the engine can only rotate at a speed much lower than the idling speed. In addition, the noise caused by gear ringing is large.

  On the other hand, the output pressure of the fluid pressure motor is determined by the fluid pressure and the motor capacity, and does not depend on the rotational speed. Further, since the output density is higher than that of the electric starter, a sufficient starting torque can be output to the engine with a small reduction ratio. Furthermore, the fluid pressure motor has low noise and quickly overcomes the resonance region with the vehicle body, so there is little vibration and quick return from an idling stop or the like is possible.

  Therefore, in the technique described in Patent Document 1, it is conceivable to start the engine by operating the fluid pressure pump / motor as a motor at the accumulator pressure as proposed in the technique described in Patent Document 2. There is a problem.

  That is, the fluid pressure motor has a low volumetric efficiency in a low rotation region of 500 rpm or less, and the engine start is a rotation from 0 rpm, so the rotation speed region does not match. In addition, although the accumulator has a high output density, the energy density is low, so it is necessary to shorten the time used for the motor as much as possible.

  Accordingly, an object of the present invention is to solve the above-mentioned inconveniences and to provide an engine start control device for a fluid pressure assist vehicle provided with a fluid pressure assist mechanism and capable of starting the engine in the shortest possible time by a fluid pressure pump / motor. Is to provide.

In order to achieve the above object, according to claim 1, an engine mounted on a vehicle and a fluid pressure pump / motor connected to the engine via a clutch and disposed in a fluid pressure supply circuit. An accumulator connected to the fluid pressure pump / motor in the fluid pressure supply circuit, and the operation of the fluid pressure pump / motor between the pump and the motor when energized by being inserted in the fluid pressure supply circuit. And switching the fluid pressure pump / motor as a pump driven by the engine through the electromagnetic switching valve to discharge the fluid pressure and accumulate the pressure in the accumulator. While the deceleration energy is regenerated, the fluid pressure pump / motor is connected to the motor via the electromagnetic switching valve when the vehicle starts or accelerates. In the engine start control device for a fluid pressure assist vehicle, the engine start control device includes a fluid pressure assist mechanism that assists driving of the engine with the fluid pressure accumulated in the accumulator. An engine start request determining means for determining and a fluid accumulated in the accumulator by operating the fluid pressure pump / motor as a motor via the electromagnetic switching valve when it is determined that the engine start request is made. When it is determined that the fluid pressure supply start means for starting the pressure supply and the rotational speed of the fluid pressure pump / motor have reached the first rotational speed, and have reached the first rotational speed; A clutch engaging means for engaging the clutch; and determining whether or not the engine speed has reached the second speed after the clutch is engaged. When it is determined to have reached the second rotational speed, and a ignition means for igniting the engine, together with the first rotation speed is a value set based on complete explosion rotational speed of said engine, said first 2 rpm was constructed as Ru value der to be set higher than the first speed.

  In the engine start control device for a fluid pressure assist vehicle according to claim 1, when it is determined that the engine start request is made, the fluid pressure pump / motor is operated as a motor via the electromagnetic switching valve. When supply of the fluid pressure accumulated in the accumulator is started and it is determined that the rotation speed of the fluid pressure pump / motor has reached the first rotation speed, the clutch is engaged, and after the clutch is engaged, the engine rotation When it is determined that the number has reached the second rotational speed, the engine is ignited so that the engine can be started in the shortest possible time by the fluid pressure pump / motor.

  That is, when the fluid pressure pump / motor idles and reaches the first rotation speed, in other words, in order to reduce the usage time in the region where the volumetric efficiency of the fluid pressure pump / motor is low, the rotation speed is increased. Since the clutch is engaged and the engine is rotated, and the engine is ignited when the second rotational speed is reached, the engine can be started in as short a time as possible.

  As a result, the amount of fluid required for starting can be reduced, the capacity of the accumulator can be reduced, and when the fluid is engine lubricating oil or the like, the discharge amount of HC (hydrocarbon) can also be reduced.

  Furthermore, since the output density is higher than that of the electric starter, it can output a sufficient starting torque with a small reduction ratio to the engine, and the noise is small, and the vibration region is quickly overcome, so there is less vibration. Quick return from idling stop is also possible.

Further , since the first rotational speed is a value set based on the complete explosion rotational speed of the engine and the second rotational speed is set to a value set higher than the first rotational speed , the first, first, The starting time can be further shortened by appropriately setting the number of two revolutions.

1 is a schematic diagram showing an overall engine start control device for a fluid pressure assist vehicle according to an embodiment of the present invention. It is a hydraulic circuit diagram which shows operation | movement of HAS (fluid pressure assist mechanism) in the apparatus shown in FIG. It is a flowchart which shows operation | movement of the apparatus shown in FIG. 3 is a time chart showing the operation of the flow chart. It is explanatory drawing explaining the characteristic of the fluid pressure pump / motor in HAS of FIG. It is explanatory drawing which shows the engine start by the fluid pressure pump / motor in HAS of FIG. 1 compared with an electric starter.

  DESCRIPTION OF EMBODIMENTS Hereinafter, an embodiment for implementing an engine start control device for a fluid pressure assist vehicle according to the present invention will be described with reference to the accompanying drawings.

  FIG. 1 is a schematic view generally showing an engine start control device for a fluid pressure assist vehicle according to an embodiment of the present invention, and FIG. 2 shows an operation of a HAS (fluid pressure assist mechanism) in the device shown in FIG. It is a hydraulic circuit diagram.

  In FIG. 1, reference numeral 10 indicates an engine. The engine 10 is composed of an internal combustion engine that uses spark-ignition gasoline having four cylinders, and is mounted on a vehicle 14 that includes left and right drive wheels (front wheels; only one of left and right is shown) 12. The vehicle 14 is partially indicated by the engine 10 and the drive wheels 12.

  The throttle valve 16 disposed in the intake system of the engine 10 is mechanically disconnected from the accelerator pedal 20 disposed on the vehicle driver's seat floor, and a DBW (Drive By Wire) mechanism 22 comprising an actuator such as an electric motor. And is opened and closed by the DBW mechanism 22.

  The intake air metered by the throttle valve 16 flows through the intake manifold 24 and mixes with fuel injected from an injector (not shown) near the intake port of each cylinder to form an air-fuel mixture. When the valve is opened, it flows into the combustion chamber (not shown) of the cylinder. The air-fuel mixture is ignited and combusted in the combustion chamber, and after driving the piston to rotate the crankshaft 10a, it is discharged to the outside of the engine 10 as exhaust.

  The rotation of the crankshaft 10 a is input to a continuously variable transmission (hereinafter referred to as “CVT”) 30 via a torque converter 26. Although not shown, the CVT 30 is a drive pulley disposed on a main shaft (transmission input shaft) connected to the torque converter 26 and a driven pulley disposed on a counter shaft (transmission output shaft) parallel to the main shaft MS. It consists of a pulley and an endless flexible member such as a metal belt stretched between them.

  The rotation of the countershaft CS is transmitted to the differential 32 through a gear fixed to the secondary shaft, and from there to the left and right drive wheels 12. A disc brake (brake) 34 is disposed in the vicinity of the driving wheel (front wheel) 12 and the driven wheel (rear wheel, not shown). The disc brake 34 includes a caliper 34a in which a brake pad is incorporated, a disc rotor 34b that contacts and brakes the caliper 34a, and the like.

  A brake pedal 36 is disposed on the vehicle driver's seat floor. The brake pedal 36 is connected to the disc brake 34 via a master back 40 and a master cylinder 42. The master cylinder 42 includes a reservoir 42a that stores brake fluid, and a piston (not shown) that is slidable in an oil chamber filled with the brake fluid stored in the reservoir 42a. When the driver depresses the brake pedal 36, the depressing force is increased by the master back 40 and transmitted to the master cylinder 42.

  The piston of the master cylinder 42 strokes for a distance corresponding to the increased stepping force. The brake fluid pressure (brake fluid pressure) generated by the stroke of the piston is sent to the disc brake 34 of the drive wheel 12 via the conduit 42b, and the disc brake 34 is operated to brake (decelerate) the vehicle 14.

  Further, in addition to a brake mechanism (which can be operated by the driver) including a brake pedal 36, a master back 40, and a master cylinder 42, the disc brake 34 is also connected to a BBW (Brake By Wire) mechanism 44. When the brake fluid pressure is sent through 44a, it operates to brake the vehicle 14.

  A HAS (Hydraulic Assist System) 50 is connected to the engine 10.

  The HAS 50 is interposed in the fluid pressure supply circuit 52, the fluid pressure pump / motor 54 disposed in the fluid pressure supply circuit 52, the accumulator 56 connected to the fluid pressure pump / motor 54 in the fluid pressure supply circuit 52, and the fluid pressure supply circuit 52. , An electromagnetic switching valve 60 for switching the operation of the fluid pressure pump / motor 54 between the pump and the motor when energized, and an electromagnetic clutch 62 are provided. The fluid pressure pump / motor 54 is a circumscribed gear pump. Hereinafter, the fluid pressure pump / motor 54 is simply referred to as a “pump” 54.

  Since the lubricating oil (engine oil, hydraulic oil) of the engine 10 is used as the working fluid, the HAS 50 is attached to the lower part in the gravity direction of the cylinder block (not shown) of the engine 10 and stores an oil pan. Housed inside.

  In addition to the pump 54, a second hydraulic pump is disposed in the fluid pressure supply circuit 52. The second hydraulic pump is driven by the engine 10 to pump up the lubricating oil from the oil pan and supply it to each part of the engine 10 as well as the fluid pressure of the CVT 30. Another hydraulic pump is arranged in the supply circuit. Similarly, it is driven by the engine 10 and pumps hydraulic oil (ATF) from the reservoir and supplies it to the torque converter 26 and the CVT 30. These hydraulic pumps are directly connected to this embodiment. The illustration is omitted because it is not related.

  A first sprocket 54a is fixed to the crankshaft 10a of the engine 10, a second sprocket 54c is fixed to the output shaft 54b of the pump 54, and a chain 54d is formed between the first and second sprockets 54a and 54c. It is handed over. Thus, the pump 54 is connected to the engine 10 via the first and second sprockets 54a and 54c and the chain 54d, and is further connected to the drive wheel 12 via the engine 10. The rotation ratio between the first sprocket 54a and the second sprocket 54c is 1: 1.3.

  The electromagnetic clutch 62 is interposed between the second sprocket 54c and the output shaft 54b of the pump 54. When the electromagnetic clutch 62 is energized from a battery (not shown), the second sprocket 54c and the output shaft 54b of the pump 54 are connected while the second sprocket 54c and the output shaft 54b of the pump 54 are energized. Disconnect the connection. The first and second sprockets 54a and 54c, the output shaft 54b of the pump 54, the electromagnetic clutch 62, and the like are disposed outside the cylinder block.

  The HAS 50 operates the fluid pressure pump / motor 54 as a pump driven by the engine 10 (or the drive wheel 12) via the electromagnetic switching valve 60 when the vehicle 14 is decelerated, and discharges hydraulic pressure (fluid pressure) to accumulator 56. When the vehicle 14 is starting or accelerating, the fluid pressure pump / motor 54 is operated as a motor via the electromagnetic switching valve 60, and the engine 10 is operated with the fluid pressure accumulated in the accumulator 56. It is comprised so that the drive (rotation) may be assisted.

  The accumulator 56 has a cylinder shape as is well known with nitrogen gas sealed therein. The HAS 50 includes a plurality of accumulators 56 in order to increase the pressure accumulation capacity as much as possible.

  As schematically shown in FIG. 2A, the electromagnetic switching valve 60 includes a spool 60a that is slidably accommodated inside a valve body (not shown). The spool 60a is brought into contact with the plunger 60b11 of the electromagnetic solenoid 60b1 at one end and is urged toward the other end by the spring 60c1. Further, the other end of the spool 60a is brought into contact with the plunger 60b21 of the electromagnetic solenoid 60b2, and is biased toward the other end by the spring 60c2.

  In the electromagnetic switching valve 60, when the electromagnetic solenoid 60b1 or 60b2 protrudes the plunger 60b11 or 60b21 by current supply (energization or excitation) from the battery 64 or stop of current supply (deenergization or demagnetization), the spool 60a Accordingly, it is configured to advance and retreat between one end side and the other end side.

  Referring to FIG. 2, the electromagnetic switching valve 60 is driven when the pump 54 is operated as a motor (when starting or accelerating. FIG. 2B), and when regenerating when operating as a pump (when decelerating. In order to move the spool 60a so that the necessary hydraulic fluid flow path is established in accordance with the figure (c)) and the neutral position between them (when the pump 54 and the accumulator 56 are not connected, the figure (a)). Energization of the electromagnetic solenoids 60b1 and 60b2 is controlled.

  Hereinafter, in detail, in the fluid pressure supply circuit 52, the spool 60a of the electromagnetic switching valve 60 has first, second, third, fourth, fifth and sixth ports 60a1, 60a2, 60a3, 60a4, 60a5. It has a land shape in which six ports of 60a6 are formed.

  The fifth and sixth ports 60a5 and 60a6 are always connected regardless of the position of the spool 60a, while the connection from the first port 60a1 to the fourth port 60a4 is switched according to the position of the spool 60a.

  The first port 60a1 is connected to a reservoir (oil pan) 52b via an oil passage 52a as shown in FIGS. 2 (a), 2 (b) and 2 (c), while the second port 60a2 is shown in FIG. 2 (b). In this way, it is connected to the accumulator 56 through a source pressure restricting portion 52c that appropriately adjusts the discharge pressure of the pump 54, and is connected to the input (inlet) side of the pump 54 through the oil passage 52d.

  As shown in FIG. 2C, the third port 60a3 is connected to the accumulator 56 on the one hand, and is connected to the output side of the pump 54 via the check valve 52e and the oil passage 52f on the other hand. The fourth port 60a4 is connected to the input side of the pump 54 via the oil passages 52g and 52d.

  The fifth port 60a5 is connected to the output side of the pump 54 via the oil passage 52h. The sixth port is connected to the engine (E) 10 via an oil passage 52i, more specifically to a portion requiring lubrication such as a piston and a connecting rod, and further via an oil passage 52j (specifically, inside the cylinder block). Is dropped along a connecting rod or the like) and connected to the reservoir 52b.

  As shown in FIG. 2C, a relief pressure restricting section 52k is formed between the fifth and sixth ports 60a5 and 60a6 to relieve the discharge pressure of the pump 54 when it is excessive.

  When the vehicle 14 travels in a low engine load state, the neutral time shown in FIG. 2A is set, and energization of the electromagnetic solenoids 60b1 and 60b2 is stopped.

  In the neutral state, the first and second ports 60a1 and 60a2 are connected, and the connection between the pump 54 and the accumulator 56 through the second port 60a2 (or the third port 60a3) is cut off. It operates as a normal hydraulic pump driven by the engine 10 (or drive wheel 12).

  That is, the pump 54 is driven by the engine 10 or the like to pump hydraulic oil (lubricating oil) from the reservoir 52b through the oil passages 52a and 52d and discharge it to the oil passage 52h. The discharged hydraulic oil (hydraulic pressure) is supplied to the portion requiring lubrication of the engine 10 through the oil passage 52i, and returns to the reservoir 52b through the oil passage 52j.

  On the other hand, when the vehicle 14 decelerates, the regeneration is shown in FIG. 2C, the electromagnetic solenoid 60b1 shown in FIG. 2A is energized, and the spool 60a is driven to the other side (right side in FIG. 2). .

  During regeneration, the first and second inlet ports 60a1 and 60a2 are connected as in the neutral state, and the pump 54 operates as a normal hydraulic pump driven by the engine 10 (or drive wheels 12), and the reservoir 52b The hydraulic oil is pumped up through the oil passages 52a and 52d and discharged to the oil passage 52h.

  The discharged hydraulic oil is supplied to the lubrication required portion of the engine 10 and then returned to the reservoir 52b. At this time, since the pump 54 and the accumulator 56 are connected via the third port 60a3, the hydraulic fluid (hydraulic pressure) discharged to the oil passage 52h passes through the oil passage 52f while pushing up the check valve 52e. Is supplied to the accumulator 56, where it is accumulated (deceleration energy is regenerated).

  Further, when the vehicle 14 starts or accelerates, the driving shown in FIG. 2B is performed, the electromagnetic solenoid 60b2 shown in FIG. 2A is energized, and the spool 60a is driven to one side (left side in FIG. 2). Is done. During driving, the first and second ports 60a1 and 60a2 are disconnected, and the second port 60a2 is connected to the accumulator 56. The third and fourth ports 60a3 and 60a4 are connected.

  As a result, the hydraulic oil (hydraulic pressure) accumulated in the accumulator 56 is supplied to the pump 54 via the oil passage 52d, and the pump 54 is rotated. The hydraulic fluid (hydraulic pressure) output from the pump 54 is supplied to the engine 10 and the reservoir 52b through the oil passage 52h, while being supplied through the oil passage 52f, the check valve 52e, and the third and fourth ports 60a3 and 60a4. Returned to pump 54.

  Returning to the description of FIG. 1, the pump 54 is operated as a hydraulic motor during driving as described above. The rotation of the pump 54 is transmitted from the output shaft 54b to the crankshaft 10a of the engine 10 through the electromagnetic clutch 62, the first and second sprockets 54a and 54c, and the chain 54d, and the engine 10 (and possibly the drive wheels 12). Assists driving (rotation).

  A crank angle sensor 70 is provided at an appropriate position such as near the cam shaft (not shown) of the engine 10 and outputs a signal indicating the engine speed NE for each predetermined crank angle position of the piston. In the intake system, an absolute pressure sensor 72 is provided at an appropriate position downstream of the throttle valve 16 and outputs a signal proportional to the intake pipe absolute pressure (engine load) PBA.

  The actuator of the DBW mechanism 22 is provided with a throttle opening sensor 74 and outputs a signal proportional to the opening TH of the throttle valve 16 through the rotation amount of the actuator.

  The output of the crank angle sensor 70 and the like described above is sent to the engine controller 80. The engine controller 80 includes an ECU (Electric Control Unit) including a microcomputer including a CPU, ROM, RAM, I / O, and the like.

  An accelerator opening sensor 82 is provided near the accelerator pedal 20 and outputs a signal proportional to the accelerator opening AP corresponding to the driver's accelerator pedal operation amount. A brake switch (BKSW) 84 is provided in the vicinity of the brake pedal 36 and outputs a signal indicating the driver's brake pedal operation.

  A pressure sensor 86 is disposed in the conduit 42b of the master cylinder 42, and indicates a fluid pressure (brake fluid pressure) generated in response to the driver's operation of the brake pedal 36, in other words, a pressure substantially corresponding to the brake pedaling force. Produces output. A first rotation speed sensor 90 is disposed on a drive shaft (not shown) in the vicinity of the drive wheel 12 and outputs a signal indicating the vehicle speed (the traveling speed of the vehicle 14) through the rotation of the drive wheel 12.

  A second rotation speed sensor 92 is disposed in the vicinity of the output shaft 54b of the pump 54, and generates an output indicating the rotation speed (HAS rotation speed) of the pump 54. In the fluid pressure supply circuit 52, first, second, and third pressure sensors 94, 96, 100 are arranged on the input side and output side of the pump 54 and in the vicinity of the accumulator 56, and the hydraulic pressure in the oil passages 52d, 52h An output corresponding to the hydraulic pressure (ACM pressure) accumulated in the accumulator 56 is generated.

  In the fluid pressure supply circuit 52, a temperature sensor 102 is disposed in the reservoir 52b and outputs a signal corresponding to the oil temperature (HAS oil temperature). The electromagnetic clutch 62 is provided with a contact switch 104, which outputs an ON signal when the electromagnetic clutch 62 is engaged (connected).

  The output of the accelerator opening sensor 82 and the like described above is sent to the HAS controller 110. The HAS controller 110 is also composed of an ECU (Electric Control Unit) including a microcomputer composed of a CPU, ROM, RAM, I / O, and the like.

  Further, a CVT controller 120 is provided for controlling the operation of the torque converter 26 and the CVT 30. Similarly to the engine controller 80 and the HAS controller 110, the CVT controller 120 is also composed of an ECU. The engine controller 80, the HAS controller 110, and the CVT controller 120 are connected to each other through a bus 122 so that they can communicate with each other.

  The CVT controller 120 is supplied with the output of a rotational speed sensor (both not shown) that generates outputs indicating the input rotational speed NDR, the output rotational speed NDN, etc. of the CVT 30. The CVT controller 120 controls the operation of the CVT 30 and the torque converter 26 based on the output of these sensors and the vehicle speed, accelerator opening, etc. obtained by communicating with the HAS controller 110 through the bus 122.

  Similarly, the engine controller 80 controls operations such as fuel injection and ignition timing of the engine 10 based on the input sensor output or the output obtained from another controller obtained through the bus 122, and the operation of the DBW mechanism 22. To control. A BBW controller (not shown) is also provided to control the operation of the BBW mechanism 44.

  The HAS controller 110 also controls the operation of the HAS 50 based on the similarly input sensor output or the output obtained from another controller obtained through the bus 122.

  The control of the operation of the HAS 50 will be described with reference to FIG. 2 again. When the HAS controller 110 determines that the vehicle 14 is in a steady running state, the HAS controller 110 determines that it is neutral and the spool 60a is in FIG. The energization to the electromagnetic solenoids 60b1 and 60b2 of the electromagnetic switching valve 60 is stopped so as to form the flow path shown.

  The HAS controller 110 determines that the vehicle 14 is in a driving state when the vehicle 14 is determined to be in a start or acceleration state from the output of the accelerator opening sensor 82 or the like, and forms the flow path shown in FIG. When it is determined from the output of the brake switch 84 or the like that the vehicle 14 is in a decelerating state, it is determined that the vehicle is being regenerated, and the electromagnetic solenoids 60b1 and 60b2 are energized so as to form the flow path shown in FIG. Control.

  FIG. 3 is a flowchart showing details of the processing of the HAS controller 110 therein, and FIG. 4 is a time chart showing the processing.

  In the following, the start mode determination is performed in S10. More specifically, it is determined that a request for starting the engine 10 is made. Since the engine controller 80 detects that the ignition key has been turned on by the driver, the start request of the engine 10 is determined by the HAS control 110 communicating with the engine controller 80.

  Next, the process proceeds to S12 and the HAS 50 is reset. That is, the energization to the electromagnetic solenoid 60b1 or 60b2 and the electromagnetic clutch 62 of the electromagnetic switching valve 60 is set to the initial value (zero).

  Next, in S14, the electromagnetic solenoid 60b1 or 60b2 of the electromagnetic switching valve 60 is energized to drive at the time of driving in FIG. 2B, and the hydraulic pressure is supplied from the accumulator 56 to the pump 54 to operate the pump 54 as a motor.

  Since the electromagnetic clutch 62 is not engaged, the pump 54 idles and leaks a small amount of hydraulic oil from the seal portion. That is, by applying a pressure to the fluid pressure supply circuit 52, the low rotation region (region where the volumetric efficiency is low) of the pump 54 is surely overcome.

  Next, in S16, the hydraulic pressure supplied to the pump 54 is detected from the output of the first pressure sensor 94, and it is determined whether or not the detected hydraulic pressure has increased. When the result in S16 is negative, the program proceeds to S18, where the HAS 50 is set in a standby state, and the program proceeds to S20, where it is determined that the engine cannot be started.

  On the other hand, when the result in S16 is affirmative, the routine proceeds to S22, where it is determined (determined) whether or not the HAS rotational speed detected from the second rotational speed sensor 92 has reached the first rotational speed (for example, 200 rpm). The first rotational speed is set based on a value near the complete explosion speed of the engine 10, in other words, the complete explosion speed.

  When the result in S22 is negative, the process returns to S16. When the result is affirmative, the process proceeds to S24, where an energization circuit (not shown) of the electromagnetic clutch 62 is energized from the battery 64 and the electromagnetic clutch 62 is engaged. As a result, the engine 10 is connected to the pump 54 rotating at a rotation speed equal to or higher than the first rotation speed by the pump 54, and is motored at once.

  FIG. 5 is an explanatory diagram showing the characteristics of the pump 54. As shown in the figure, the efficiency of the pump 54 decreases in the low rotation region, so that the region can be quickly overcome to reduce the amount of oil consumed.

  Next, the process proceeds to S26, where it is determined again whether the hydraulic pressure supplied to the pump 54 detected from the output of the first pressure sensor 94 has increased.

  On the other hand, when the result in S26 is affirmative, the program proceeds to S28, in which it is determined (determined) whether or not the engine speed NE detected from the crank angle sensor 70 has reached the second speed (for example, 400 rpm).

  When the result in S28 is negative, the process returns to S26, while when the result is positive, the process proceeds to S30, and the HAS 50 is set in a standby state. The reason why the HAS 50 is set to the standby state is to reduce the amount of oil consumed by the HAS 50.

  Next, in S32, ignition of the air-fuel mixture in the combustion chamber of the engine 10 is executed. At this time, since the rotational speed of the engine 10 exceeds 400 rpm, the engine 10 completes explosion without trouble and rotates autonomously. Next, in S34, it is determined that the engine 10 has been started.

As described above, in this embodiment, the engine 10 mounted on the vehicle 14 is connected to the engine 10 via the clutch (electromagnetic clutch) 62 and the fluid disposed in the fluid pressure supply circuit 52. A pressure pump / motor 54, an accumulator 56 connected to the fluid pressure pump / motor 54 in the fluid pressure supply circuit 52, and the fluid pressure pump / motor 54 when the fluid pressure supply circuit 52 is energized. An electromagnetic switching valve 60 for switching the operation of the motor 54 between the pump and the motor is provided, and the fluid pressure pump / motor 54 is driven by the engine 10 via the electromagnetic switching valve 60 when the vehicle 14 is decelerated. And the accumulator 56 accumulates pressure to regenerate deceleration energy, while the vehicle 14 generates power. At the time of acceleration or acceleration, a fluid pressure assist mechanism (HAS) that operates the fluid pressure pump / motor 54 as a motor via the electromagnetic switching valve 60 and assists the driving of the engine 10 with the fluid pressure accumulated in the accumulator 56. In the engine start control device (HAS controller 110) of the fluid pressure assist vehicle having 50, an engine start request determining means for determining whether or not a start request for the engine 10 has been made, and a start request for the engine 10 are made. can to be determined that the fluid pressure supply to start supplying the electromagnetic via switching valve 60 the fluid pressure pump / motor 54 is operated as a motor fluid pressure that is accumulated in the accumulator 56 (hydraulic) Start means (S12, S14) and the rotation speed of the fluid pressure pump / motor 54 (HAS rotation) ) Has reached the first rotational speed, and when it is determined that the first rotational speed has been reached, clutch fastening means (S16, S22, S24) for fastening the clutch 62, and the clutch 62 Is determined, it is determined whether or not the rotational speed of the engine 10 has reached the second rotational speed, and when it is determined that the second rotational speed has been reached, ignition means for igniting the engine 10 (S32) Thus, the engine 10 can be started in the shortest possible time by the fluid pressure pump / motor 54.

  That is, when the fluid pressure pump / motor 54 idles and reaches the first rotation speed, in other words, as shown in FIG. 5, the usage time in the region where the volume efficiency of the fluid pressure pump / motor 54 is low is reduced as much as possible. Therefore, the engine 10 is rotated by engaging the clutch 62 after the rotation is increased, and the engine 10 is ignited when the second rotation speed is reached, so that the engine 10 is started in as short a time as possible. Can do.

  As a result, the amount of fluid required for starting can be reduced, the capacity of the accumulator 56 can be reduced, and when the fluid (working fluid) is engine lubricating oil or the like, the amount of HC discharged can also be reduced.

  Furthermore, as shown in FIG. 6, since the output density is higher than that of an electric starter used at a relatively low speed, a sufficient starting torque (exceeding the starting lower limit torque) can be achieved with a small reduction ratio with respect to the engine. In addition to being able to output power, the noise level is low, and the resonance region with the vehicle body is quickly overcome, so there is little vibration and quick return from idling stop is possible.

  In addition, the first rotational speed is a value set based on the complete explosion rotational speed of the engine 10, and the second rotational speed is a value set higher than the first rotational speed. In addition to the effects described above, the starting time can be further shortened by appropriately setting the first and second rotational speeds.

  In the above description, the lubricating oil of the engine 10 is used as the working fluid, but it is not limited thereto. The working fluid may be anything as long as it is an incompressible fluid, and may be brake fluid, ATF, water, air, or the like.

  Moreover, although the gasoline engine which uses gasoline as a fuel was shown as an engine, it is not limited to this, a diesel engine which uses light oil as fuel may be used, or a hybrid vehicle of a gasoline engine (or diesel engine) and an electric motor. It may be.

  Further, although the CVT (continuously variable transmission) 30 is used as the transmission, it is not limited thereto, and a stepped transmission, a dual clutch type, or the like may be used. Furthermore, the endless flexible member of the CVT is not limited to the belt, but may be a chain. The clutch 62 may also be wet instead of electromagnetic.

  10 engines (internal combustion engines), 12 drive wheels, 14 vehicles, 16 throttle valves, 20 accelerator pedals, 22 DBW mechanisms, 26 torque converters, 30 CVT (continuously variable transmission), 34 disc brakes, 36 brake pedals, 40 master backs , 42 master cylinder, 44 BBW mechanism, 50 HAS (fluid pressure supply mechanism), 52 fluid pressure supply circuit, 52a, 52d, 52f, 52g, 52h, 52i, 52k oil passage, 52b reservoir, 54 fluid pressure pump / motor ( Pump), 56 accumulator, 60 electromagnetic switching valve, 60a spool, 60b1, 60b2 electromagnetic solenoid, 70 crank angle sensor, 72 absolute pressure sensor, 74 throttle opening sensor, 80 engine controller, 82 accelerator opening sensor, 84 brakes Pitch, 86,94,96,100 pressure sensors, 90 and 92 rotational speed sensor, 102 temperature sensor, 110 HAS controller, 120 CVT controller, 122 bus

Claims (1)

An engine mounted on a vehicle, a fluid pressure pump / motor connected to the engine via a clutch and disposed in a fluid pressure supply circuit, and connected to the fluid pressure pump / motor in the fluid pressure supply circuit And an electromagnetic switching valve for switching the operation of the fluid pressure pump / motor between the pump and the motor when energized through the fluid pressure supply circuit, and when the vehicle decelerates, the electromagnetic switching The fluid pressure pump / motor is operated as a pump driven by the engine through a valve to regenerate deceleration energy by discharging fluid pressure and accumulating pressure in the accumulator, while the vehicle is starting or accelerating. Fluid stored in the accumulator by operating the fluid pressure pump / motor as a motor via the electromagnetic switching valve In the engine start control device for a fluid pressure assist vehicle provided with a fluid pressure assist mechanism for assisting driving of the engine, an engine start request determination means for determining whether or not the engine start request is made, Fluid pressure supply start means for starting the supply of fluid pressure accumulated in the accumulator by operating the fluid pressure pump / motor as a motor via the electromagnetic switching valve when it is determined that a start request is made; Determining whether or not the rotational speed of the fluid pressure pump / motor has reached the first rotational speed, and when it is determined that the rotational speed has reached the first rotational speed, clutch fastening means for fastening the clutch; and the clutch After the engine is engaged, it is determined whether or not the engine speed has reached the second engine speed. When it is determined that the engine speed has reached the second engine speed, And a ignition means for igniting said together with the first rotation speed is a value set based on complete explosion rotational speed of said engine, said second value rpm is set higher than the first rotational speed engine start control device of the hydraulic assist vehicle, characterized in that it.

Images