JP2013019457A - Connected hst vehicle and its control method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a connected HST vehicle which can easily be connected with an HST vehicle at low costs, and does not cause a mechanical trouble and human errors, and its control method.SOLUTION: A main vehicle 11 and a sub-vehicle 12 obtain traveling power from HSTs 3 (3s, 3j) which are driven by an engine 1, respectively. A variety of pieces of information are input to a controller 5 of each vehicle from the engine 1 and a transmission (traveling transmission 4) of each vehicle. Connectors 6s, 6j of the main vehicle 11 and the sub-vehicle 12 are connected to each other by using a connection cable 7, and the information is transferred by connecting the controllers 5 of both the vehicles. By controlling the HST 3j of the sub-vehicle 12 so that loads of both the vehicles coincide with each other on the basis of the acquired information, load statuses of the respective vehicles are controlled so as to be the same.

Description

  The present invention relates to a connected HST vehicle and a control method thereof.

  Snow removal vehicles, construction work vehicles, and the like using a hydrostatic continuously variable transmission (hereinafter referred to as “HST”) as a drive system are well known and disclosed in, for example, Patent Document 1. The HST is composed of at least one of a variable displacement hydraulic pump and a hydraulic motor, and controls the traveling speed by controlling the flow rate of the hydraulic pump or hydraulic motor (controlling the swash plate angle).

FIG. 4 shows a configuration example of a typical HST of 1 pump / 1 motor type. FIG. 5 shows a typical HST configuration example of a two-pump / two-motor type.
By the way, in a track motor car and a heavy goods transport vehicle, a plurality of HST vehicles may be connected and used. FIG. 6 is a hydraulic circuit diagram when two two-pump / two-motor HST-equipped vehicles are connected.

  When two HST vehicles that are assumed to be used in linked running are connected and used, conventionally, in order to eliminate the HST pressure difference between the vehicles, both high-pressure pipes are hydraulically connected (inching). And synchronized. That is, as shown in FIG. 6, the high-pressure pipe A of the vehicle 1 and the high-pressure pipe A of the vehicle 2 are connected by the inter-vehicle inching circuit 101, and the high-pressure pipe B of the vehicle 1 and the high-pressure pipe B of the vehicle 2 are connected between the vehicles. Connection is made by the inching circuit 102.

Table 2005/054720

  Thus, conventionally, when two HST vehicles are connected and used, two sets (A, B) of each vehicle are used in order to prevent the efficiency from decreasing due to individual differences of each HST device, differences due to loads, and the like. The high pressure pipes are hydraulically connected (inching) to eliminate the pressure difference and synchronize.

  However, since the inching circuit between the vehicles is a high-pressure pipe of 30 MPa or more, it is a costly part, and the hose hardness is high (and therefore hard), so that it is difficult to handle during connection work. There was a problem that it took time.

  Furthermore, as a result of the hydraulic oil being sent from the drain circuit of the HST to the low-load vehicle side, a circuit (not shown in FIG. 6) for returning the oil to the original vehicle is also required, and oil leakage due to an increase in the number of connections There has been a problem that it has also become a cause of human error such as a mechanical trouble such as a connection error.

  The present invention solves the above-mentioned problems when a plurality of HST vehicles are connected, and can connect HST vehicles easily at low cost, and is connected without causing mechanical troubles or human error. It is an object to provide an HST vehicle and a control method thereof.

  According to the present invention, according to the present invention, in a connected HST vehicle in which a plurality of HST vehicles using an HST as a drive system are connected, engine load information of another vehicle connected to the host vehicle is acquired by communication, and the acquired other This is solved by controlling the HST of the host vehicle and / or other vehicle so that the load of each vehicle becomes the same based on the engine load information of the vehicle.

In addition, when the vehicle speed is less than a predetermined value, it is preferable that the control for making the loads of the respective vehicles be the same.
In addition, when the difference between the engine load of the host vehicle and the engine load of the other vehicle is within a predetermined range, it is preferable that the control for making the loads of the respective vehicles be the same.

Further, it is preferable that the increase / decrease amount of the HST control command value in the control target vehicle is a value obtained by multiplying the engine torque of the control target vehicle by the engine torque of the non-control target vehicle and a predetermined proportional constant.
Further, it is preferable that the control command value of HST in the control target vehicle is a value obtained by adding the increase / decrease amount to the current command value.

  Further, according to the present invention, in the HST control method for a connected HST vehicle in which a plurality of vehicles using HST are connected to the drive system, the engine load information of another vehicle connected to the host vehicle is acquired by communication. The problem is solved by controlling the HST of the host vehicle and / or other vehicle so that the load of each vehicle becomes the same based on the acquired engine load information of the other vehicle.

  According to the connected HST vehicle or the HST control method of the present invention, the engine load information of other vehicles connected to the host vehicle is acquired by communication, and the load of each vehicle is the same based on the acquired engine load information of the other vehicles. Since the HST of the own vehicle or / and other vehicles is controlled so that the high-pressure piping of the HST of each vehicle is not hydraulically connected (inching), the HST vehicle can be easily coupled at low cost, Mechanical troubles and human error can be prevented in advance.

In addition, since the oil amount adjusting mechanism for adjusting the oil amount between the vehicles can be eliminated, the cost for connection can be reduced.
Further, it is possible to prevent a decrease in efficiency due to a load difference in each vehicle, an individual difference in HST, a swash plate position error caused by hysteresis characteristics, and the like.

With the configuration of the second aspect, the driver's operation can be prioritized in the case of low speed traveling.
According to the configuration of the third aspect, when the load difference between the vehicles is small, the driver's operation can be prioritized.

With the configuration of the fourth aspect, it is possible to perform control corresponding to the difference in engine torque of each vehicle linearly.
With the configuration of the fifth aspect, by setting an upper limit for the increase in the control command value, the control command value does not continue to increase even when the engine of the other vehicle stops at a load of 100%.

It is a figure which shows typically the structure of the drive system in an example of the working vehicle which concerns on this invention. It is a flowchart which shows an example of an engine load synchronous process. It is a graph which shows an example of an engine load synchronous function, and a table | surface which shows the relationship between the output and torque for every engine speed. It is a hydraulic circuit diagram showing a typical configuration example of a 1-pump and 1-motor type HST. It is a hydraulic circuit diagram which shows the structural example of typical HST of a 2 pump and 2 motor type | mold. It is a hydraulic circuit diagram at the time of connecting two 2 pump and 2 motor type HST loading vehicles.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a diagram schematically showing a configuration of a drive system in an example of a work vehicle according to the present invention. The work vehicle 10 shown in this figure is obtained by connecting a first vehicle 11 and a second vehicle 12 (in the case of a track vehicle traveling on a track, connecting the vehicles is also referred to as “multiple connection”). . In the present embodiment, the first vehicle 11 will be described as a main vehicle, and the second vehicle 12 will be described as a slave vehicle. In FIG. 1, the main vehicle 11 and the slave vehicle 12 are distinguished from each other by adding a suffix “s” or “j” to the reference numerals of the main components of each vehicle. When it is necessary to distinguish the elements, a subscript is added, and when it is not necessary to distinguish, the subscript is omitted.

  The basic configuration of the main vehicle 11 and the slave vehicle 12 is the same, and each includes an engine 1, a power distributor 2, an HST (hydrostatic continuously variable transmission) 3, a traveling transmission 4, and a controller (controller) 5. Yes. The output of the engine 1 is input to the power distributor 2, and traveling power is taken out via the HST 3 and the traveling transmission 4. Reference numeral 21 of the power distributor 2 is an input shaft, and reference numeral 22 is an output shaft. When a working device such as a rotary snow removal device is provided, working power for driving the working device is taken out from the distributor output shaft 22. Depending on the configuration of the work vehicle, the working power may not be taken out by the vehicle on one side (for example, the slave vehicle 12) (the work device is not connected to the output shaft 22), or the work device is mounted on both the master and slave vehicles. Some do not (for example, heavy goods trucks).

  The HST 3 has a hydraulic pump 31 and a hydraulic motor 32. In the figure, it is shown with a 1 pump / 1 motor type configuration, and for example, a configuration as shown in FIG. 4 can be used. The hydraulic pump 31 is driven by power from the distributor output shaft 22, and the hydraulic motor 32 is rotated by receiving pressure oil from the hydraulic pump. In the configuration of FIG. 4, the hydraulic pump 31 is a variable displacement type, and the hydraulic motor 32 is a fixed displacement type. It is also possible to use a two-pump / two-motor type HST as shown in FIG. The hydraulic motor 32 is connected to the input shaft 41 of the traveling transmission 4, and traveling power is taken out from the output shaft 42 of the transmission, and rotates a wheel (not shown).

  Various types of information as shown in Table 1 below are input to the controller 5 from the engine 1 and transmission (traveling transmission 4) of each vehicle. Parameters relating to the engine and transmission input to the controller 5 in this embodiment are in accordance with the SAE J1939 standard. The various parameters shown here are merely examples, and the present invention is not limited to these.

  In this embodiment, a connector 6 for transferring information between the main vehicle 11 and the slave vehicle 12 is provided in each vehicle. By connecting the connectors 6s and 6j of each vehicle using a connection cable (communication cable) 7, the controllers 5 of both vehicles are connected to each other, and data and control information are transferred by CAN (controller area network) communication. To do. Based on the information acquired in this manner, the load status of each vehicle can be controlled to be the same by controlling the HST 3j of the vehicle so that the load of each vehicle becomes the same. This eliminates the need for hydraulic connection (inching), and makes it possible to eliminate the inching piping and the oil amount adjusting mechanism in the conventional configuration as shown in FIG.

  The work vehicle 10 according to the present embodiment is obtained by connecting the main vehicle 11 and the slave vehicle 12, but the load of each vehicle is not necessarily the same, and there is a pressure difference between the HSTs 3 s and 3 j in each connected vehicle. Arise. Therefore, the swash plate of the HST hydraulic pump 31 is controlled based on the information on the engine and transmission shown in Table 1 of the other vehicle received via the connection cable 7 so that the load of each vehicle becomes the same. As a result, the load status of HST3 (3s, 3j) of each vehicle can be made the same, and the pressure difference between HST3s, 3j can be eliminated and synchronized in the same manner as when hydraulically connected (inching). It becomes.

  In the present embodiment, the slave vehicle 12 is configured to control the HST 3j of the slave vehicle 12 (control the swash plate of the hydraulic pump 31j) based on the received information of the master vehicle 11. In this embodiment, the control of the HST 3j in the slave vehicle 12 is performed by the controller 5j of the slave vehicle 12.

  FIG. 2 is a flowchart showing an example of engine load synchronization processing in the present embodiment. In this flow, first, in S1, it is determined whether or not the vehicle to be controlled is a cascaded slave vehicle. If “No”, the process proceeds to S8 to perform normal control (pump command by a normal travel lever provided in the HST). Value control), increase / decrease stepwise up to the target command value, and finish the synchronization process.

  In the case of “Yes (slave trained vehicle)” in S1, the process proceeds to S2 to check whether the vehicle speed is equal to or higher than the set value. If the vehicle speed is less than the setting, the process proceeds to S8 and normal control is performed. On the other hand, when the vehicle speed is equal to or higher than the set value, the process proceeds to S3, and it is checked whether or not the difference in engine torque between the main vehicle 11 and the slave vehicle 12 is within the set range. If it is within the set range, the process proceeds to S8 and normal control is performed. On the other hand, if the engine torque difference between the main vehicle and the slave vehicle exceeds the set range, the process proceeds to S4, and whenever 100 milliseconds (0.1 seconds) elapses, the process proceeds to S5 and the timer (100 milliseconds timer) is set. Set and proceed to S6.

  In S6, the pump command value increase / decrease value is obtained by multiplying the engine torque of the own vehicle (subordinate vehicle 12) from the engine torque of the main vehicle (the difference in engine load between the main and subordinate vehicles) and a predetermined proportional constant. And In step S7, the pump command value is set to the current pump command value + the increase / decrease amount of the pump command value, and the synchronization processing routine is terminated.

  Note that when the main vehicle drops at an engine load of 100% (engine speed decreases), the pump swash plate of the vehicle falls down until the engine load reaches 100%, so the pressure control provided in the hydraulic circuit Upper limit to increase / decrease of command value (inclination amount calculated backward from vehicle speed, engine speed, gear position + α) to cope with the case where the command value continues to increase even if the swash plate is not tilted from the command value due to the valve working Is set.

  In the case of a one-pump / multi-motor type HST configuration applied to a heavy-duty vehicle or the like, by setting the upper limit, it is possible to prevent over-rotation of the motor when wheel load loss of a specific motor shaft occurs. it can.

  In addition, as described in the notes (*) 1, 2, and 3 in the figure, the engine torque of the main vehicle (ratio to the maximum torque at the current rotational speed) is determined by CAN communication between the controllers (controllers 5s and 5j). Receive. The engine torque of the host vehicle is received by CAN communication with an ECU (Engine Control Unit). The actual torque can be calculated from the ratio of the engine torque to the maximum torque at the current rotational speed, but it is not performed in this embodiment.

  FIG. 3 shows a graph showing an example of a load synchronization function of the engine 1 mounted on the work vehicle 10 of this embodiment, and a table of output and torque for each engine speed. As can be seen from these graphs and tables, the engine 1 of this example exhibits a maximum torque in the vicinity of 1400 rpm (rpm), and thereafter the torque decreases as the engine speed increases. On the other hand, the output increases with the number of revolutions, and reaches the maximum output at about 1800 revolutions.

  In the present embodiment, the second vehicle 12 controls the HST of the host vehicle (slave vehicle) {acquires engine load information of another vehicle (main vehicle) connected to the host vehicle (slave vehicle) through communication, and The HST of the own vehicle (slave vehicle) is controlled so that the load of each vehicle becomes the same based on the engine load information of the other vehicle. However, the first vehicle 11 controls the HST of the other vehicle (slave vehicle). {The engine load information of the other vehicle (slave vehicle) connected to the own vehicle (main vehicle) is acquired by communication, and the load of each vehicle is the same based on the acquired engine load information of the other vehicle. The HST of the vehicle (subordinate vehicle) may be controlled}.

  Further, the present invention can be applied to a configuration in which three or more HST vehicles are connected. For example, this can be dealt with by setting the first vehicle 11 as the own vehicle and controlling the HST of two other vehicles (slave vehicles). Alternatively, the HST of the own vehicle and the HST of another slave vehicle (other vehicle) may be controlled from one slave vehicle (own vehicle).

  As described above, in the present invention, even when a plurality of HST vehicles are connected, it is not necessary to hydraulically connect (inch) the high-pressure piping of the HST of each vehicle, and the connection cable 7 exchanges electrical signals. Since it is only necessary to connect, since there is no need to use a high-pressure pipe that is hard and difficult to handle, connection work is easy, connection errors can be prevented, and connection costs can be reduced. An oil amount adjusting mechanism for adjusting the oil amount between the vehicles can also be eliminated.

  And under the simple connection work such as the connection of the communication cable as described above, the simplification of the configuration and the cost reduction, the load situation of each connected vehicle can be made the same. It is also possible to prevent a decrease in efficiency due to a difference in load, an individual difference in HST, an error in the position of the swash plate due to hysteresis characteristics, and the like.

  As mentioned above, although this invention was demonstrated by the example of illustration, this invention is not limited to this. For example, in the case of a configuration in which two two-pump two-motor type HST-equipped vehicles are connected, the load state of each vehicle can be controlled to be the same. Further, the control of HST is not limited to the hydraulic pump, and the hydraulic motor may be controlled.

  As the configuration of the HST, an appropriate configuration including the configurations shown in FIGS. 4 and 5 can be adopted. Further, the configuration of each vehicle is arbitrary, and an appropriate configuration including the configuration of a power distributor, a traveling transmission, and the like can be adopted. The engine of the vehicle can adopt any prime mover including a diesel engine and a gasoline engine.

  In the case of a rotary snowplow, it is not limited to road driving, and may be a track snowplow traveling on a track or a road-rail vehicle capable of traveling on a road and a track. Furthermore, the work vehicle is not limited to a rotary snowplow, and the present invention can also be applied to a construction work vehicle such as a wheel loader or a heavy-duty carrier vehicle.

1 engine (motor)
2 Power distributor 3 HST (hydrostatic continuously variable transmission)
4 Traveling transmission 5 Controller (controller)
6 Connector 7 Connection cable 10 Work vehicle 11 First vehicle (main vehicle)
12 Second vehicle (secondary vehicle)
31 Hydraulic pump 32 Hydraulic motor 101, 102 Inter-vehicle inching circuit

Claims (6)

In a connected HST vehicle in which a plurality of HST vehicles using the HST as a drive system are connected,
The engine load information of other vehicles connected to the own vehicle is acquired by communication, and the HST of the own vehicle and / or other vehicles is set so that the load of each vehicle becomes the same based on the acquired engine load information of the other vehicles. A connected HST vehicle characterized by controlling.   2. The connected HST vehicle according to claim 1, wherein when the vehicle speed is less than a predetermined value, the control for making the load of each vehicle the same is not performed.   2. The connected HST vehicle according to claim 1, wherein when the difference between the engine load of the host vehicle and the engine load of another vehicle is within a predetermined range, the control for making the load of each vehicle the same is not performed. .   The increase / decrease amount of the HST control command value in the control target vehicle is a value obtained by multiplying the engine torque of the control target vehicle from the engine torque of the non-control target vehicle by a predetermined proportional constant. The connection HST vehicle of any one of Claims 1-3.   The connected HST vehicle according to claim 4, wherein a control command value of HST in the control target vehicle is a value obtained by adding the increase / decrease amount to a current command value. In an HST control method for a connected HST vehicle in which a plurality of vehicles using HST are connected to a drive system,
The engine load information of other vehicles connected to the own vehicle is acquired by communication, and the HST of the own vehicle and / or other vehicles is set so that the load of each vehicle becomes the same based on the acquired engine load information of the other vehicles. HST control method characterized by controlling.

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