SE529528C2 - Automatic shift manipulation - Google Patents

Abstract

The control device (100) for the transmission unit comprises a cylinder (105) with two inlets (110,120) and a piston (130) moving between two stop positions (150,160) inside the cylinder (105). A first flow (F1) is guided through the first inlet (110) before the control unit (100) initiates the motion of the fluid (F2) through the second inlet (120) when the piston (130) is positioned in the second final position (160). The first flow (F1) pushes the piston (130) in a first direction (150) while the second flow (F2) directs the piston (130) towards the second position (160). Independent claims are given for a vehicle with the transmission system installed, a method for the control of the system, a computer program suitable for the control of the individual steps, and a device for saving the program on.

Description

20 25 30 529 528 2 der and a piston arrangement.

WO90103523 describes an alternative solution for damping a gear shift device in its end position. Here is a back pressure chamber designed as an extinguishing groove in the front surface of the piston.

Said chamber contains compressed air which is released through a narrow passage when the piston reaches the bottom, whereby the impact force of the piston is reduced. The back pressure chamber is located radially inwards in relation to the cylinder wall, so that the piston rings around the perimeter of the piston are not affected by the high back pressure.

However, all the prior art piston damping constructions are mechanically complicated. Thus, the solutions are relatively error-prone and / or expensive to implement.

SUMMARY OF THE INVENTION The object of the present invention is therefore to provide a solution which allows a reliable, cost-effective and uncomplicated gear control means which has a smooth and low-noise method.

According to one aspect of the invention, the object is achieved by the gear control system initially described, the gear control unit being adapted to operate the gear manipulation device so that, when the piston is in the first end position and the at least one gear control command indicates the piston is to be moved to the second end position. the first fluid flow is caused to be supplied through the first inlet before the second fluid flow is caused to be supplied through the second inlet. Analogously, when the piston is in the second end position and the at least one gear control command indicates that the piston is to be moved to the first end position, the second fluid flow is caused to be supplied through the second inlet before the first fluid flow is caused to be supplied through the first inlet.

An important advantage of this system is that it allows a very uncomplicated cylinder-and-piston construction to operate the gear shift mechanism. Since the proposed damping reduces the mechanical stress on the cylinder body, the gear handling device can also be designed with a relatively thin wall thickness. In addition, existing gear control systems can be easily modified to implement the proposed system.

According to embodiments of this aspect of the invention, the gear control unit is adapted to operate the gear handling device so that (i) the supply of the first fluid flow is interrupted at the latest when the supply of the second fluid flow is initiated (possibly no fluid flow is supplied to the cylinder body for a period before the second fluid flow is initiated), or (ii) the supply of the second fluid flow is initiated before the supply of the first fluid flow is interrupted.

Depending on the implementation and the desired relationship between speed and damping, different of these options may be advantageous. In general, by shortening the interval between the first and second fluid flows, the damping effect is increased, and vice versa. The actual damping effect is de facto determined by the ratio between the total amounts of fluid supplied through the first and the second inlet, respectively. Consequently, the damping effect can also be adjusted by controlling the magnitudes of the fluid flows.

According to other embodiments of this aspect of the invention, therefore, the gear control unit is adapted to operate the gear manipulation device so that (a) the first and second fluid flows have substantially equal magnitudes in the steady state, (b) the first fluid flow has a steady state magnitude exceeding a steady state magnitude of the second fluid flow, or (c) the second fluid flow has a steady state magnitude exceeding a steady state magnitude of the first fluid flow. According to another aspect of the invention, the object is achieved by the motor vehicle initially described, which includes the system proposed above.

According to yet another aspect of the invention, the object is achieved by the method initially described, wherein when the piston is in the first end position and is to be moved to the second end position the method involves initiating a supply of the first fluid flow through the first inlet before a supply of the second fluid flow through the second inlet is initiated.

Of course, depending on what is defined about the first and the second end position, respectively, the method may just as well include initiating a supply of the second fluid flow through the second inlet before a supply of the first fluid flow through the first inlet is initiated when the piston is in the second end position and must be moved to the first end position.

The advantages of this method, as well as the preferred embodiments thereof, will be apparent from the discussion above with reference to the proposed arrangement.

According to a further aspect of the invention, the object is achieved through a computer program directly storable to the internal memory of a computer, the program comprising software for controlling the method proposed above when said program is run on a computer.

According to another aspect of the invention, the object is achieved by a computer-readable medium with a program stored thereon, the program being adapted to cause a computer to control the method proposed above.

BRIEF DESCRIPTION OF THE DRAWINGS The present invention will now be explained in more detail by means of embodiments, which are described by way of example, and with reference to the figures.

Figures 1a-d illustrate the general operating principle of a gear manipulation device according to an embodiment of the invention; shows diagrams exemplifying further embodiments of the operating principle of the device in Figures 1a-d; Figures 2a-c Figure 3 schematically shows a motor vehicle which includes a gear steering system according to an embodiment of the invention; and Figure 4 shows a flow chart illustrating the general method of the invention.

DESCRIPTION OF EMBODIMENTS OF THE INVENTION We refer initially to Figure 1a, which shows a gear manipulation device 100 according to an embodiment of the invention.

The gear manipulating device 100 is adapted to effect at least one gear shift operation with respect to a gearbox, i.e. to change gear up or down), or to switch between a high or low range. Figures 1b-d show later phases of a functional procedure according to the embodiment of the invention, which is initiated in Figure 1a.

The device 100 includes a cylinder body 105 having a first inlet 110 and a second inlet 120 for receiving a first fluid flow F1 and a second fluid flow F2, respectively. Fluid flows F1 and F2 can be represented by compressed air (as well as other gases) or by a hydraulic fluid. Figures 2a-c illustrate the fluid flows F1 and F2 as functions over time according to different embodiments of the invention.

We now return to Figure 1a, where a shift piston 130 is movable between a first end position 150 and a second end position 160 within the cylinder body 105. The piston 130 is moved towards the first end position 150 as a result of the first fluid flow F1, and towards the second end position 160. as a result of the second fluid flow F2. A piston rod 140 is connected to the piston 130, 529 528 and preferably a actuator 145 connected to the distal end of the piston rod 140. The means 145 is in turn adapted to manipulate a primary shift function when it is in a first position A corresponding to the piston 130 being in the first end position 150, and a secondary shift function B corresponding to the piston 130 being in the second end position 160. Figure 1a thus shows a situation where the primary shift function is made possible. Now, at t = 0, we assume that the shift manipulator 100 is ordered to effect the secondary shift function. According to the invention, the first fluid flow F1 is initially fed through the first inlet 110, so that the interior of the cylinder body 105 to which the piston 130 is to be moved is pre-pressurized. This is because it generates the desired damping effect with respect to the piston movement.

Then, at a slightly later time t = t1, the second fluid flow F2 is supplied through the second inlet 120. This situation is shown in Figure 1b. At t = t1, the first fluid flow F1 can either be interrupted as shown in Figure 2a, or continue as illustrated in Figure 2c. As another alternative, the first fluid flow F1 may have been interrupted even before t = t1. This embodiment of the invention is illustrated in Figure 2b.

After t = t1, as the second fluid flow F2 continues to be supplied to the cylinder body 105, the shift piston 130, the piston rod 140 and the actuating means 145 are moved in a direction SD towards the second end position 160 and the second position B, respectively. s a phase at a further later time t = tg during this movement. A reversed fluid flow out of the first inlet 110 is referred to herein as F3. Finally, at a time t = t3, positions 160 and B have been reached, and the piston 130 stops. This phase is shown in Figure 1d. Thus, the fluid flows can be interrupted.

We now return to Figure 2a where we see a diagram of the fluid flows discussed above as functions of time. The vertical axes reflect a flow magnitude f, and the horizontal axes indicate the time t. The first fluid flow F1 / F3 is represented here by a dashed line, while the second fluid flow F2 is represented by a solid line. As can be seen from Figure 2a, the first flow F1 is interrupted around t = tj, i.e. when the supply of the second fluid flow F2 is initiated. Therefore, the reverse flow F3 is also initiated out of the first inlet 110 around t = tj. Provided that the first and second inlets 110 and 120, respectively, have the same, or at least comparable characteristics (for example in terms of flow resistance), F2 z F3. In this embodiment of the invention, the first fluid flow F1 has a steady state magnitude f1, which exceeds a steady state magnitude f2 of the second fluid flow F2. Given a positive flow direction into the cylinder body 105, the fluid flow F3 has a magnitude -f3 in the stationary state with approximately the same absolute value as the magnitude f2 in the stationary state of the second fluid flow F2.

Figure 2b shows a diagram of an embodiment of the invention in which the operating procedure includes a period during which no fluid flow is supplied to the cylinder body 105 before the supply of the second fluid flow F2 is initiated. Already at t = t11 (where tj> t11> 0) the first fluid flow F1 is interrupted. Thus, the cylinder body 105 does not receive any fluid flow via the inlets 110 or 120 during t = t11 to t = tj. Instead, during this period, a small amount of fluid leaks out of the first inlet 110 in the form of a fluid flow F3.

Then, from t = tj, the function procedure is analogous to the procedure described above with reference to Figure 2a. Here, however, the first and second fluid flows F1 and »F2 have substantially the same magnitudes f1 and f2, respectively, in steady state.

Figure 2c shows a diagram of an embodiment of the invention in which, in contrast to the embodiments described above, the operating procedure includes a period during which the first and second fluid flows F1 and F2 overlap in time t.

Accordingly, the supply of the second fluid flow F2 is initiated before the supply of the first fluid flow F1 is interrupted. In this specific example, the first fluid flow continues to t = t21 (where t21> t1).

During a period t = t1 to t = t21, the cylinder body 105 thus "receives" fluid flows via both inlets 110 and 120. Provided that the cylinder body 105 has no openings beyond these inlets 110 and 120, the net fluid flow with respect to the cylinder body 105 must of course be zero. Therefore, if, for example, f2> f1 as illustrated in Figure 2c, the first inlet 110 will deliver an outgoing flow (i.e. F3) when t1 <t <t21. From t = t21 onwards, the function procedure is analogous to the procedure described above with reference to Figure 2a.

Nevertheless, in the embodiment according to Figure 2c, the second fluid flow F2 has a magnitude f2 in the stationary state, which exceeds a magnitude f1 of the first fluid flow F1 in the stationary state.

As mentioned earlier, any combination is conceivable of relations between the magnitudes f1 and f2 in the steady state and the time when the second fluid flow F2 is initiated in relation to when the first fluid flow F1 is interrupted as described above according to the invention. These are design parameters that are selected depending on the special requirements of the application.

Figure 3 schematically shows a motor vehicle 300, which includes a gear control system according to an embodiment of the invention. The system includes a gearbox 320 and a gear control unit 330.

The gearbox 320 is in turn arranged on a driveline of the vehicle 300. Typically, this means that the gearbox 320 has a mechanical connection 325a with a power source, for example a motor 310, and another mechanical connection 325b with a drive wheel shaft 340, so that a driving torque can be transmitted from the power source 340 to the shaft 340 via the gearbox 320. The gearbox 320 also has a gear manipulation device 100 which is adapted to effect at least one gear shift operation with respect to the gearbox 320. The gear manipulation device 100 is in turn 529 528 9 configured as described above with reference to Figures 1a-d.

The gear control unit 330 is adapted to operate the gear manipulation device 100 in response to at least one gear control command (not shown in Figure 3). This command can either be initiated manually, for example if the gearbox 320 is of a manual type, or be generated automatically, for example if the gearbox 320 is of the automatic type. The gear control unit 330 is further adapted to operate the gear manipulation device 100 according to the function procedure described above with reference to Figures 1a-d and 2a-c. Thus, when the piston 130 is in the first end position 150 and the at least one shift control command indicates that the piston 130 is to be moved to the second end position 160, the first fluid flow F1 is supplied through the first inlet 110 before the second fluid flow F2. analogously, when the piston 130 is in the second end position 160 and the at least one shift control command indicates that the piston 130 is to be moved to the first end position 150, the second fluid flow F2 is caused to - is passed through the second inlet 120 before the second fluid flow F2 is caused to be supplied through the first inlet 110.

Preferably, the Shift Control Unit 330 includes a computer readable medium, or is linked to such a medium, which stores a program for controlling the unit 330 according to the principle proposed above.

In order to summarize, the general method according to the invention for controlling the gear manipulation device 100 will now be described with reference to the flow chart in Figure 4.

A first step 410 controls whether or not the reciprocating piston is to be moved (that is, either from the first end position to the second, or from the second to the first). If no such command has been received, the procedure loops back and stops in step 410. Otherwise, a step 415 follows. This step 415 checks the switching piston is currently in the first end position, and if so, , follows a step 420. Otherwise, that is, if the shift piston is currently in the second end position, a step 440 follows.

Step 420 initiates a supply of the first fluid flow F1 through the first inlet 110 to the cylinder body 105. Then, depending on the application, follows either a step 425 which stops the first fluid flow F1, or a step 430, wherein a supply of the second fluid flow F2 through the second inlet 120 to the cylinder body 105 is initiated. In either case, step 425 is completed before proceeding to a subsequent step 435. This step 435 checks whether or not the shift piston has reached the second end position, and if so, the procedure loops back to step 410. Preferably, a sensor detects if the piston has reached the end position, or a timer is used. In the latter case, step 435 tests whether the timer has expired or not. If it is found in step 435 that the shift piston has not yet reached the second end position, the procedure loops back to step 430 for further supply of the second fluid flow F2.

Step 440 initiates a supply of the second fluid flow F2 through the second inlet 120 to the cylinder body 105. Then, depending on the application, follows either a step 445 which stops the second fluid flow F2, or a step 450, wherein a supply of the first the fluid flow F1 through the first inlet 110 to the cylinder body 105 is initiated. In either case, step 445 is completed before the procedure proceeds to a subsequent step 455. This step 455 checks whether the shift piston has reached the first end position or not, and if so, the procedure loops back to step 410. Preferably, a late sensor - check if the piston has reached the end position, or a timer is used. In the latter case, step 455 tests whether the timer has expired or not. If it is found in step 455 that the shift piston has not yet reached the second end position, the procedure loops back to step 450 for further supply of the second fluid flow F1. All the procedural steps, as well as any sub-sequence of steps, described with reference to Figure 4 above can be controlled by means of a programmed computer apparatus. In addition, although the embodiments of the invention described above with reference to the figures include a computer and processes performed in a computer, the invention extends to computer programs, especially computer programs on or in a carrier adapted to practically implement the invention. The program may be in the form of source code, object code, a code which constitutes an intermediate between source and object code, such as in partially compiled form, or in any other form suitable for use in implementing the process according to the invention. The carrier can be any entity or device which is capable of carrying the program. For example, the carrier may comprise a storage medium such as a flash memory, a ROM (Read Only Memory), for example a CD (Compact Disc) or a semiconductor ROM, EPROM (Electrically Programmable ROM), EEPROM (Erasable EPROM), or a magnetic recording medium, such as a floppy disk or hard disk. In addition, the carrier may be a transmitting carrier such as an electrical or optical signal, which may be conducted through an electrical or optical cable or via radio or otherwise. When the program is formed by a signal which can be conducted directly by a cable or other device or means, the carrier can be constituted by such a cable, device or means. Alternatively, the carrier may be an integrated circuit in which the program is embedded, where the integrated circuit is adapted to perform, or to be used in performing, the current processes.

The invention is not limited to the embodiments described in the figures, but can be varied freely within the scope of the claims.

Claims (17)

10 15 20 25 30 35 529 528 12 Patent claims A gear control system comprising: a gearbox (320) adapted to be mounted on a vehicle driveline (325a, 325b), the gearbox (320) having a gear manipulation device (100) adapted to effect at least one gear shift operation with respect to the gearbox ( 320), wherein the gear manipulating device (100) comprises: a cylinder body (105) having a first inlet (110) and a second inlet (120), and a shift piston (130) movable between a first end position (150) and a second end position (160) inside the cylinder body (105) in response to a first fluid flow (F1) supplied via the first inlet (110) and a second fluid flow (F2) supplied via the second inlet (120), respectively, and a gear control unit (330) adapted to operate the gear manipulation device (100) in response to at least one gear control command, characterized in that the gear control unit (330) is adapted to operate the gear manipulation device (100) so that: when the piston (130) is in the first position ä the end position (150) and the at least one gear control command indicates that the piston (130) is to be moved to the second end position (160), the first fluid flow (F1) is brought through the first inlet (110) before the second fluid flow (F2) is brought to be supplied through the second inlet (120), and when the piston (130) is in the second end position (160) and the at least one gear control command indicates that the piston (130) is to be moved to the first end position (150) the second fluid flow (F2) is supplied through the second inlet (120) before the first fluid flow (F1) is supplied through the first inlet (110). The system according to claim 1, characterized in that the gear control unit (330) is adapted to operate the gear manipulation device (100) so that the supply of the first fluid flow (F1) is interrupted (t1, t11) at the latest when the supply of the second fluid flow ( F2) initiated (U) - 10 15 20 25 30 529 528 13 The system according to claim 2, characterized in that the gear control unit (330) is adapted to operate the gear manipulation device (100) so that no fluid flow is supplied to the cylinder body (105) for a period (t1 - t11) before the supply of the second fluid flow ( F2) is initiated. The system according to claim 1, characterized in that the gear control unit (330) is adapted to operate the gear manipulation device (100) so that the supply of the second fluid flow (F2) is initiated before the supply of the first fluid flow (F1) is interrupted ( t21). The system according to any one of the preceding claims, characterized in that the gear control unit (330) is adapted to operate the gear manipulation device (100) so that the first and second fluid flows (F1, F2) have substantially equal magnitudes (f1, f2) in stationary state. The system according to any one of claims 1 to 4, characterized in that the gear control unit (330) is adapted to operate the gear manipulation device (100) so that the first fluid flow (F1) in the stationary state has a magnitude (f1) exceeding a magnetite (f2) in the steady state of the second fluid flow (F2). The system according to any one of claims 1 to 4, characterized in that the gear control unit (330) is adapted to operate the gear manipulation device (100) so that the second fluid flow (F2) in the stationary state has a magnitude (f2) exceeding a magnetite (f1) in the stationary state of the first fluid flow (F1). A motor vehicle (300) characterized in that it comprises the gear steering system according to any one of claims 1 to 7. A method of controlling a gear handling device (100) of a gearbox (320) in a motor vehicle, the gear handling device (100) comprising a cylinder body (105) and a gear piston (130) movable between a first gear 529 528 end position (150) and a second end position (160) within the cylinder body (105) in response to a first fluid flow (F1) supplied via a first inlet (110) and a second fluid flow (F2) supplied via a second inlet, respectively. (120), characterized in that when the piston (130) is in the first end position (150) and is to be moved to the second end position (160), the method comprises: initiating the supply of the first fluid flow (F1) through the first the inlet (110) before initiating the supply of the second fluid flow (F2) through the second inlet (120). The method according to claim 9, characterized in that the supply of the first fluid flow (F1) is interrupted at the latest (t1, t11) when the supply of the second fluid flow (F2) is initiated (t1). The method according to claim 10, characterized in that, before the supply of the second fluid flow (F2) is initiated, the method comprises a period (t1 - tu) during which no fluid flow is supplied to the cylinder body (105). The method according to claim 9, characterized by initiating (t1) the supply of the second fluid flow (F2) before the supply of the first fluid flow (F1) is interrupted (t21). The method according to any one of claims 9 to 12, characterized in that the first and second fluid flows (F1, F2) have substantially equal magnitudes (f1, f2) in the stationary state. The method according to any one of claims 9 to 12, characterized in that the first fluid flow (F1) in the stationary state has a magnitude (f1) exceeding a magnitude (f2) in the stationary state of the second fluid flow (F2). The method according to any one of claims 9 to 12, characterized in that the second fluid flow (F2) in the stationary state has a magnitude (f2) exceeding a magnitude (f1) in the stationary state of the first fluid flow (F1) . A computer program directly downloadable in the internal memory of a computer, the program comprising software for controlling the steps according to any one of claims 9 to 15 when said program is run on the computer. A computer readable medium (335) having a program stored thereon, the program being adapted to cause a computer to control the steps of any of claims 9 to 15.