FI20225708A1 - Work machine and method in work machine power transmission - Google Patents

Abstract

The working machine has a first power transmission unit, which includes a motor (19), a gearbox (20) and moving means (13), and a second power transmission unit, which includes a motor (19), a gearbox (20) and moving means (13). The gearbox (20) has at least two gears and mechanical power transmission. The gearboxes (20) are controlled so that when the gear of the working machine (1) is changed, the gear of the first gearbox (20) is changed while the gear of the second gearbox (20) is engaged. Here, at least one power transmission unit produces traction for the work machine (1) during the gear change.

Description

Work machine and method in the power transmission of the work machine

Background of the invention

The invention is related to work machines and especially to the power transmission of work machines.

Machines can be used in difficult off-road conditions, where the movement of the machine requires traction and ability from the power transmission. On the other hand, for example, in order to carry out the transfer drive smoothly, the speed of the machine must be sufficient in this case. Therefore, quite diverse requirements are placed on the characteristics of the power transmission of the work machine.

Brief description of the invention

The aim of the invention is to develop a new type of work machine and a method for power transmission of work machines. The solution according to the invention is characterized by what is said in the independent patent claims. Some embodiments of the invention are the subject of independent patent claims.

In the presented solution, the working machine has a first power transmission unit with an engine, gearbox and means of movement, and a second power transmission unit with an engine, gearbox and means of movement. Gearboxes have at least two gears and a mechanical transmission. In this context, the gearbox can also be called a gearbox. The gearboxes are controlled in such a way that when changing the gear of the work machine, while one gearbox is changing gear, the gear of the other gearbox is engaged. The fact that the gearbox gear is engaged means that the gearbox is not shifting. In this case, during the shift, at least one power transmission unit produces traction for the machine. According to one embodiment, the gearboxes are controlled in such a way that when changing the gear of the working machine, the gearbox of the first power transmission unit

The gears of the gearbox of the N 25 continuous power transmission unit are changed one after the other. One

According to embodiment N, the gearboxes have a free area between the gears 3 to enable gear changing on the move and when changing the gear of the machine 2, the state of the gearboxes is monitored and the first gearbox = is allowed to shift into neutral only if the gear of the second gearbox is engaged. a © 30 With the presented solution, the power transmission can be realized in its structure

O simply and reliably. By using gearboxes, motors a can produce both sufficient torque when working, for example, and sufficient no-

N feet, for example, in transfer driving without the motors having to be dimensioned to directly produce the power required by different situations. One advantage of gears is that the actual engine can be made to work in a better efficiency range and thus the engine remains affordable in terms of size, weight and costs. In this way, the motors can be dimensioned optimally. Even when changing gears, the work machine remains under control reliably. During the changeover, the machine is never idle, which means that when working on slopes, for example, it is possible to avoid the machine running downhill without having to activate, for example, the machine's brake system. It is still possible to avoid the work machine rushing downhill.

Brief description of the patterns

The invention will now be explained in more detail in connection with some embodiments, with reference to the attached drawings, of which:

Figure 1 shows a work machine;

Figure 2 shows another work machine;

Figure 3 schematically shows a work machine and its power transmission; and

Figure 4 shows a block diagram according to one embodiment of changing the gear of a work machine.

Detailed description of the invention

Figures 1 and 2 show some work machines. Work machine 1 can advantageously comprise a mobile work machine 1 and especially preferably a mobile work machine 1 that can be adapted to move on an inclined and/or uneven surface. Such a mobile work machine can be, for example, a forest work unit, for example a loader tractor, as in Figure 1, a harvester, as in Figure 2, or other forest machine, for example another type of driving machine suitable for transporting loads or a combination of loader tractor and harvester, or other mobile work machine, such as a mining machine or an excavator.

The work machine 1 can comprise one or more body parts 11 and at least one

N 25 I make a boom 14 fitted to the body part. The machine can also include, for example

N a tool 16 adapted to the boom 14. The tool can comprise, for example, a lifting device 3, such as a loading bucket, and/or a wood processing tool, such as a harvester head. 2 Depending on the design, the work machine 1 can also include other structural elements. The work machine 1 can, for example, comprise at least one body part 11 adapted to

N 30 tun cab 12. Work machine 1 further comprises moving means 13, which move

The means 13 can comprise at least one of the following: wheels fitted to an axle, wheels fitted to a rocking axle, wheels fitted to a bogie axle, a chassis or

N other means, known in their own right, for guiding a work machine into motion relative to its work platform. The work machine 1 can be frame-controlled, or the work machine 1 can be controlled by controlling the means of movement 13. It is clear to a professional in the field,

that the work machine 1 additionally typically comprises numerous different structural and functional structural parts and entities depending on the type of work machine, such as the load compartment 15, the power source 17 and so on.

Work machine 1 is shown schematically in Figure 3. In the embodiment of Figure 3, work machine 1 has two body parts 11. Body parts 11 are connected to each other by a joint 18 so that work machine 1 is body-controlled.

There is a motor 19 connected to both frame parts 11. The motor 19 can be, for example, an electric motor or a hydraulic motor or any other suitable motor. The motor 19 is connected to the means of movement 13 with a gearbox 20.

In the embodiment of Figure 3, the means of movement 13 comprise wheels fitted to the bogie axle. Motor 19 is connected to the bogie shaft. In this case, the power transmission unit consists of the engine 19, the gearbox 20 and the bogie axle and the wheels fitted to it. As stated above, the means of movement 13 can comprise different solutions. A work machine according to one embodiment can have a motor in connection with each or at least several wheel hubs, which is connected to the wheel by a gearbox comprising at least two speed ranges. In this case, the power transmission unit consists of the engine, gearbox and wheel.

The gearbox 20 has at least two gears. Furthermore, the gearbox20 has a mechanical transmission and a free range between the gears. The gearbox 20 can also be described with the terms shift-on-fly or powershift. When the gear is changed, the speeds of motor 19 and gear 20 must be synchronized. In this case, the gear is idle for a short time, and therefore during this time the gearbox 20 does not transmit the torque from the motor 20 to the means of movement 13. The gearbox 20, however, enables the gear to be changed on the move. Such a gearbox 20 is reliable and durable

N ative and reasonably simple in structure.

AN The machine 1 still has a control unit 30. The control unit 30 is suitable

It is designed to control engines 19 and gearboxes 20, for example.

E for climbing. The control unit 30 further controls the operation of the gearboxes 20 so that when changing the gear, the gear of one power transmission unit is changed to another

S time than the gear of the second power transmission unit. In this case, at least together all the time

In the N power transmission unit, traction is maintained and rolling of the machine can be avoided.

N 35 The gearbox 20 does not necessarily have to have a free area between the gears. Even in this case, it is advantageous to take a little load off the gearbox during the shift by controlling it with the control unit. In this case, the load on the gearbox during shifting can be reduced. Even then, when changing the gear of the work machine, while one gearbox is changing gear, the gear of the other gearbox is engaged. In this case, the power transmission unit whose gearbox gear is being changed does not produce at least its full amount of pulling power for the machine. Instead, in this case at least one other power transmission unit produces the main part or an essential part of the traction force for the work machine.

The block diagram in Figure 4 describes the operation of the control system of the work machine 1 according to one example during a gear change. The action starts from the situation described in block 100. In this case, both gearbox A of the first power transmission unit and gearbox B of the second power transmission unit are in the same gear. The first power transmission unit can be placed, for example, in the front part of the working machine 1 and the second power transmission unit can be placed in the rear part of the working machine, or the first power transmission unit can be placed in the rear part of the working machine 1 and the second power transmission unit in the front part of the working machine. The front and rear of the machine can be in the same frame, or the front of the machine can be formed to include its own frame and the back of the machine a frame separate from the front.

In block 101, it is monitored whether a command to change gear has been received.

This command may come automatically. For example, when working machine 1 first drives on flat terrain in a higher gear and then arrives uphill, it is possible, for example, based on the slowing down of speed and the increase in the need for torque, to conclude the need to change to a lower gear and give the command to do so automatically. The operation can also be semi-automatic, in which case the driver can, for example, give the command to change gears from the control panel of the work machine 1.

N When the command to change gears has come, the control unit 30 controls first

N of transmission A to change gears, which is illustrated by block 150. That

After A, control unit 30 directs gearbox B to change gear, which is again = illustrated with block 151. © 30 When the command to change gear has come, first the command to change gear

E tolle A switches to neutral. This is illustrated in block 102. © Then, according to block 103, we check whether the gearbox A

E switched to neutral. When neutral is engaged, the speed of motor 19 is synchronized again

For N delle gear according to block 104.

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After this, according to block 105, it is checked whether the speed of the motor 19 is synchronized to the new gear. When the speed of the motor 19 is synchronized to the new gear, gear A is controlled to the new gear according to block 106.

In block 107, it is checked that gearbox A is connected to a new gearbox. When gearbox A is switched to the new gear, we move on to switch gearbox B to the new gear.

When the information has arrived that gearbox A has been switched to a new gear, the command is first given to gearbox B to shift to neutral. This is illustrated in block 108.

After this, according to block 109, it is checked whether gearbox B is engaged in neutral. When neutral is engaged, the speed of the corresponding engine 19 is synchronized to the new gear according to block 110.

After this, according to block 111, it is checked whether the speed of the motor 19 is synchronized to the new gear. When the speed of the motor 19 is synchronized to the new gear, gear A is controlled to the new gear according to block 112

In block 113, it is checked that gearbox B is connected to a new gear. When gearbox B is also connected to the new gear, the gear change of machine 1 has been completed.

Block 120 illustrates monitoring gear A — by checking whether the gear is on or in neutral. The speeds of the engine and gearbox are still monitored to ensure synchronization.

Similarly, with block 121, it is illustrated that the transmission B is monitored in such a way that it is observed whether the transmission is on or in neutral. The engine and gearbox speeds are also monitored to ensure synchronization.

Monitoring of gearboxes A and B illustrated by blocks 120 and 121

N can also be implemented by observing the actual output from the power transmission unit

AN traction force and/or by monitoring the amount of power transmitted by the transmission.

A The operation of the gear change illustrated in Figure 4 is similar = both when the gear is changed from a smaller to a larger one and when © 30 a gear is changed from a larger to a smaller one.

E There are various delays in the operation of the gearbox. These delays can be caused, for example, by a delay in the mechanics of the gearbox or a delay in the hydraulics

S knife. Synchronizing the motor speed also takes time. These are all things

N naturally to be taken into account when determining how the functions of different gearboxes

N 35 is timed so that during the shift, at least one power transmission unit produces traction for the implement.

The solution presented here is particularly useful in connection with the loader tractor shown in Figure 1. When the loader tractor is loaded, this can happen in quite demanding off-road conditions. In this case, traction force and pulling ability are required from the power transmission of the loader tractor. On the other hand, a loader tractor can also move quite long distances on the road, for example. For example, when moving on the road or in easy terrain or with good traction, the power transmission of the loader tractor is required to be able to realize a sufficiently high speed. So that the motors 19 do not need to be dimensioned both for high speed and to produce a high torque, it is useful to use gearboxes. On the other hand, the gearbox must be reliable and durable.

In addition, gear shifting should be smooth. What's more, the loader must not skid uncontrollably, even on steep slopes.

The work machine 1 has been shown above, which has two body parts 11. The work machine can therefore also have either one body part or three body parts or even more.

Application of the presented solution is possible if the work machine is equipped with at least two power transmission units described above. The work machine 1 can also have at least three power transmission units described above. In this case, the control unit 30 can be adapted to control the gearboxes in such a way that during shifting, at least one power transmission unit produces a traction force for the work machine. Advantageously, at least half of the power transmission units are controlled to produce traction force for the work machine during shifting. Preferably, the gearboxes are controlled in such a way that only one gearbox at a time is changing gear. For example, a work machine with four power transmission units can be controlled in such a way that at least two of the power transmission units generate traction for the work machine during the change. Even in this case, preferably, during the changeover of the four power transmission units in the work machine, at least three of the power transmission units generate traction power for the work machine.

N country. Advantageously, the number of units changing at the same time is minimized so that,

AN that the best possible attraction can be kept on all the time.

A If, for example, there is a power transmission unit connected to each wheel hub, the gear change can be carried out on a wheel-by-wheel basis. Or, the © 30 gear change can be performed in such a solution by changing side-by-side

The gears of both wheels of a pair of wheels, i.e. at the same time. © According to one embodiment, gear shifting is optimized

S time to the driving situation, load, load, direction of travel (e.g. up

N hill/downhill etc.) etc. related. For example, power line motors can be

N 35 kea the best efficiency. For example, when driving with an empty machine, it would be possible to switch to a bigger gear more sensitively, because the power transmission would be able to produce enough traction. Correspondingly, with a large load, drive motors could be used at higher revolutions.

According to one embodiment, different gears can be used at different ends of the machine. If, for example, the rear undercarriage has heavy rollers, which in themselves cause a lot of losses, and the front end has no rollers, a smaller gear could be used in the power transmission of the rear undercarriage than at the same time in connection with the front end.

The presented solution is applied both when the gear is changed from a smaller to a larger one and when the gear is changed from a larger to a smaller one. On the other hand, in some cases, it may be necessary to change the gear of one transmission unit to a lower one and the gear of the other transmission unit to a higher one. Even in this case, the gear changes are advantageously carried out at different times.

The control unit 30 can have a computer program product, which comprises program code readable by a computer, which is arranged to implement the functions of the control system of the presented work machine or the steps of the method that implements the functions, when the program code is executed by the processor. The control unit 30 comprises processing means or a processor. The control unit 30 can comprise a memory in which information has been collected and stored and is being collected and stored. The processing means may be adapted to perform at least part of the method steps and/or functions presented in this explanation. In one embodiment, the processing means can be adapted to receive and send information and commands.

The processing means can comprise, for example, programmable logic and/or a programmable microprocessor. The processing means can form the control unit 30 or a part of it.

One embodiment comprises a computer program that contains program code, the execution of which on the computer causes one of the above-described direct

Functions according to the N form. A computer program may be included in a data file

AN for a readable storage medium, for example non-volatile memory.

A One embodiment comprises a computer program product that contains = a computer program according to one embodiment to perform functions according to one of the embodiments described above © 30.

E In one embodiment, the apparatus comprises processing means that © are configured to perform the functions described in one embodiment.

S Processing equipment can act as a computer to protect the execution of program code

N ten. The processing means can comprise at least one processor, memory and

N 35 platforms capable of executing program code.

Embodiments can be implemented as a computer process defined by a computer program. A computer program can be in source code format, object code format or an intermediate format between them, and the computer program can be stored on a storage medium, which can be any piece or device that can store a computer program. For example, a computer program can be stored on a computer program distribution medium that can be read by a computer or processor. The computer program distribution medium can comprise a storage medium, computer memory, read-only memory (ROM), an electronic carrier wave, a communication signal, and a software distribution package, for example.

In one embodiment, the computer program product can be stored on computer-readable media and can be executed by a processor, and the computer program product can comprise computer-readable program code.

Such a computer program product can be arranged to implement at least part of the steps of one of the methods presented above when the program code is executed on a processor.

Instead of a computer program, the functions of the presented work machine control system or the steps of the method that implements the functions can be implemented, for example, by relay control or simple logic control.

It is obvious to a professional in the field that as technology develops, the basic idea of the invention can be implemented in many different ways. The invention and its embodiments are therefore not limited to the examples described above, but may vary within the scope of the patent claims.

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Claims (12)

Patent Claims 1. A work machine, characterized by the fact that the work machine has a first power transmission unit with an engine, gearbox and means of movement, and a second power transmission unit with an engine, gearbox and means of movement, that the gearboxes have at least two gears and mechanical power transmission, and that the work machine includes a control unit that is adapted to control the gearboxes in such a way that when changing the gear of the work machine, while one gearbox is changing gear, the gear of the other gearbox is engaged, so that during the change, at least one power transmission unit produces traction force for the work machine. 2. Work machine according to claim 1, characterized in that the control unit is adapted to control the gearboxes so that when changing the gear of the work machine, the gears of the gearbox of the first power transmission unit and the gearbox of the second power transmission unit are changed one after the other. 3. Work machine according to claim 1 or 2, characterized in that the gearboxes have a free area between the gears to enable gear changing on the move. 4. Work machine according to claim 3, characterized in that when changing the gear of the work machine, the control unit is adapted to monitor the state of the gearbox and allow the gearbox to shift to neutral only if the gear of at least one other gearbox is engaged. 5. A work machine according to one of the preceding claims, characterized by the fact that the work machine has at least two body parts. 6. A work machine according to claim 5, characterized in that at least two body parts each have at least one power transmission unit, whereby the O first body part has a first power transmission unit and the second body part has a second power transmission unit. = 7. A work machine according to one of the preceding claims, characterized in that the work machine has at least three power transmission units and the control unit E is adapted to control the gearboxes in such a way that only one gearbox at a time is changing gears. 8. A work machine according to one of the previous claims, known from the fact that the work machine is a forest machine, especially a loader tractor. No. 35 9. A method in the power transmission of a working machine, where the working machine has a first — a power transmission unit with an engine, a gearbox and means of movement, and a second power transmission unit with an engine, a gearbox and means of movement, where the gearboxes have at least two gears and a mechanical transmission, whereby the gearboxes are controlled so that when changing the gear of the work machine while one gearbox is changing gear, the gear of the other gearbox is kept engaged so that during the change at least one power transmission unit produces traction force for the work machine. 10. The method according to claim 9, where the gearboxes are controlled in such a way that when changing the gear of the work machine, the gears of the gearbox of the first power transmission unit and the gearbox of the second power transmission unit are changed one after the other. 11. The method according to claim 9 or 10, where the gearboxes have a free area between the gears to enable gear changing on the move and when changing the gear of the work machine, the state of the gearbox is monitored and the gearbox is only allowed to move to neutral if at least one gear of the other gearbox is engaged . 12. A computer program product, which computer program product is stored on computer-readable media and can be executed by a processor, and which computer program product comprises computer-readable program code, which is arranged to implement the mentioned steps of a method according to claims 9-11, when the program code is executed by the processor. N N O N © I O O I a a co O KR LO N N O N