JPH01279146A - Shift locking device for automatic transmission - Google Patents

Abstract

PURPOSE:To contrive to prevent careless starting by providing respective detecting means for the actuation of a range and a braking device and for governor hydraulic pressure based on the results of the respective detections when governor hydraulic pressure is less than a set value and when a braking device is out of action at the suspension range of a transmission. CONSTITUTION:It is detected by a brake detecting means 2 whether or not the fluid pressure of a braking device is equal to or more than a set value, a shift range is detected by a range detecting means 3, and the hydraulic pressure of a governor G is detected by a governor hydraulic pressure detecting means 4 respectively. Following which, the results of the detections from the respective detecting means 2, 3 and 4 are inputted into a control means 6. And a locking means 5 is actuated by use of line pressure as an actuating source via an accumulator 6 when the a transmission is in a suspension range, and when governor hydraulic pressure is less than the set value while a braking device is out of action. This constitution can thereby prevent a vehicle from being carelessly started.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a shift lock device for an automatic transmission having a stop range and a travel range.

(Prior art) Generally, this type of shift lock device is disclosed in, for example, Japanese Patent Application Laid-Open No. 62
As shown in Publication No. 279146, a range detection device that detects the range of the automatic transmission, a braking detection v device that detects the operation of the brake device, and the detection results of both of the above-mentioned mountain detection devices are used. and a locking device that disables shifting of the automatic transmission when the automatic transmission is shifted to a stop range, and performs a braking operation when shifting the automatic transmission from the stop range to the drive range. It is made so that the shift operation cannot be performed unless it is on.

(Problem to be Solved by the Invention) For example, while driving, there are cases where the automatic transmission is mistakenly shifted from the drive range to the neutral range, which is the stop range. In such a case, the shift lock device will work, so you will not be able to shift from the neutral range to the drive range unless you operate the brake once to release the locking operation of the 7-foot loss device even while driving. .

The present invention was developed in view of the above circumstances, and its purpose is to reliably prevent the vehicle from inadvertently starting when shifting from the stop F range to the running range when the vehicle starts. Automatic transmission shift lock device that does not lock even if the automatic transmission is shifted to the neutral range, which is the stop range, if the vehicle is running at a predetermined speed or higher. is to provide.

(Means for Solving the Problems) The present invention is based on the fact that the governor hydraulic pressure generated in the governor of an automatic transmission changes approximately in proportion to the speed of the vehicle, and in order to achieve the above-mentioned object. In a hydraulically operated automatic transmission equipped with a stop range and a travel range,
A range detection means for detecting the range, a braking detection means for detecting the operation of the brake device, a governor oil pressure detection means for detecting the governor oil pressure generated in the governor of the automatic transmission, and a detection result by each of the detection means. based on,
When the automatic transmission is shifted to the stop range and the governor oil pressure is below a predetermined value and the brake device is not operating, the automatic transmission cannot be shifted using the line oil pressure of the automatic transmission as the operating source. The invention is characterized by comprising a locking means.

(Function) According to the present invention, when the automatic transmission is shifted to the stop range, if the governor oil pressure is below a predetermined value and the brake device is not operating, the automatic transmission is shifted. This function locks the vehicle to prevent the vehicle from starting suddenly and inadvertently. On the other hand, if the vehicle is in motion and the governor oil pressure is above a predetermined value, even if the vehicle is accidentally shifted from the drive range to the stop range. Even in this case, the automatic transmission will not lock its shifts.

(Example) A shift lock device for an automatic transmission according to the present invention will be described below according to an example shown in the drawings.

The shift lock device for an automatic transmission shown in the figure is for locking an automatic transmission that can be shifted by switching a manual valve in conjunction with a shift operation of a 7-foot lever under predetermined conditions. The transmission is
The gear mechanism includes a torque converter and a locking element including a plurality of clutches, and the engaging element is actuated via an actuator including a cylinder and a hydraulically actuated piston to shift the gear. It is a pressure-operated type.

In addition, the above automatic transmissions have a parking range of i11 as a stop range.
It has a range CP) and a neutral range (N),
In addition, the driving ranges are drive range (D), second range (■), Lauren 2 (L), and reverse range (R), and the shift pattern is as known < (P) - (R). -(N)-CD)-(II)-(
L).

However, the shift lock device for the automatic transmission described above utilizes the line pressure that is the control oil pressure of the automatic transmission, the governor pressure generated in the governor of the automatic transmission, and the brake fluid pressure of the brake device (1). Basically, the brake fluid pressure generated in the brake device (1) is input as a detection signal, and the brake fluid pressure is set to a value higher than a set value at which a predetermined braking force can be obtained. braking detection means (2) for detecting whether or not; ■ a drive range (D
), a second range (■), and a range detection means () for detecting the shifted range of the automatic transmission by inputting the switching hydraulic pressure to the low range (L) as detection signals.
3); ■ governor oil pressure detection means (4) for detecting the governor oil pressure generated in the governor of the automatic transmission; and ■ locking means (5) operated by line pressure to disable shifting of the transmission.
), and (i) the transmission is shifted to the stop range based on the detection results by the range detection means (3), the braking detection means (2), and the governor oil pressure detection means (4), and the governor is in the stop range. supplying line pressure to the locking means (5) when the oil pressure and brake fluid pressure are below set values;
Control means (6) for locking the locking means (5)
It is equipped with

The brake device (1) has a known structure, in which a mask cylinder (12) is interlocked with a brake pedal (11), and a hydraulic pipe (13) extending from the mask cylinder (12) is connected to the brake pedal (11). The brake pedal (
By depressing the mask cylinder (11), the mask cylinder (1
The brake fluid pressure pressurized by the piston 2) is supplied to the wheel/cylinder (15) to brake the wheel (14).

The braking detection means (2) inputs the brake fluid pressure generated in the mask cylinder (12) and determines whether the brake fluid pressure is equal to or higher than a set value at which a predetermined braking force can be obtained. The purpose is to detect the valve chamber (21) of the valve body (21), as shown in Figure 2.
A valve body (22) with a ball valve (22a) assembled on the back side is freely movable inside the valve chamber (21a), and
A brake fluid pressure supply port (23) connected to a brake fluid pressure supply path (16) is provided on the working surface side of the valve body (21) in 1a), and a brake fluid pressure supply port (23) is provided on the back side of the valve body (21). , a control oil pressure control port (24) that connects the first control oil passage (L1), and a drain port (25) that connects the drain passage (L2) extending to the oil pan. ), the control boat (23) is opened and closed via the ball valve (22a). (22) Opening direction (second
A return spring (26) is interposed therebetween to move it in the right direction in the figure.

The above-mentioned braking detection means (2) detects the mask cylinder (
When the brake fluid pressure generated in step 12) reaches a value (a set value or higher) that can reliably brake the wheels (work 4), the valve body (22) resists the return spring (26).
The ball valve (22a) is moved forward in the left direction in FIG.
closes the control boat (24), while the brake pedal (11) is not depressed;
Or, even if the pedal is depressed, if the brake fluid pressure generated in the mask cylinder (12) is at a value (below the set value) that cannot reliably brake the wheels (14), the brake fluid pressure is Against this, the valve body (22) is moved back by the spring force of the return spring (26), and the control boat (24) is moved back to the drain port (2).
5), and the control oil pressure of the first control oil passage (L1) is released to the oil pan.

Therefore, line pressure for operating the automatic transmission is introduced into the first control oil passage (L1), and the line pressure is changed to uIrB.
It is used for hydraulic power.

As shown in FIGS. 1 and 6, the range detecting means (3) includes a first capo (31) that introduces hydraulic pressure for switching the automatic transmission to the traveling range, and a first control The second person who introduces the control hydraulic pressure in the oil passage (L1) (3)
2) and an output capo (33) that outputs the hydraulic pressure input to the first and second capo (31) and (32). , the output port (3
3) A check ball (3B) that opens and closes is loosely inserted.

In the embodiment shown in the figure, the first manual port (31) is equipped with an engaging element that operates to lock the drive range (D), the second range (■), and the low range (L). We are trying to introduce hydraulic pressure.

The range detection means (3) described above detects when the automatic transmission is switched to any one of the drive range (D), second range (■), and low range (L). 31) into the valve chamber (35), the check ball (36)
moved to the right in Figure 6, and the second human-powered boat (32
), and the hydraulic pressure is applied to the output port (3).
3).

When the automatic transmission is switched to any of the park i1E range (P), neutral range (N), and reverse range (R), the first person capo-1-(31) is equipped with hydraulic pressure. does not occur, and therefore, by depressing the brake pedal (11) as described above, the control port of the braking detection means (2) (24)
Only when the control oil passage (L1) is closed, the control oil pressure in the control oil passage (L1) is introduced into the valve chamber (35) via the second manual boat (32), and the check ball (3
6) to the left in FIG.
31), and the control hydraulic pressure is output from the first output capo) (33), whereas the control hydraulic pressure of the braking detection means (2) is closed.
4) is opened and the control oil passage (L1) is opened to the drain oil passage (L2), the control oil pressure of the first control oil passage (L1) is released to the drain pan. Control hydraulic pressure is not output from the first output capo (33).

Next, the locking means (5) is attached to a valve case (51) having a valve chamber (51a), as shown in FIGS. 3 and 4.
A through hole (52) extending coaxially with the valve chamber (51a) is formed, and the through hole (52) and the valve chamber (51a) are provided with:
A rod cane locking body (53) having a small diameter shaft part (53a) and a large diameter shaft part (53b) is provided to be freely movable, and
A piston (54) that slides within the valve chamber (51a) is loosely inserted into the small diameter shaft portion (53a) of the lock body (53),
The piston (54) can be freely moved in the axial direction only between the stepped portion (53c) of the large diameter shaft portion (53b) and the retaining ring (55) located in front of the free end side of the small diameter shaft portion (53a). On the other hand, the hydraulic pressure output from the output port (33) of the range detecting means (3) is introduced into the working chamber (56) provided on the working surface side of the piston (54). .

Moreover, the piston (54) in the valve chamber (51a)
The large diameter shaft part (53b) on the back surface and the lock body (53)
A first spring (57) is interposed between the stepped portion (53c) of the piston (54) and a spring larger than the first spring (57) is interposed between the back surface of the piston (54) and the valve case (51). A strong second spring (58) is interposed.

As shown in FIG. 4, the manual valve (7) of the automatic transmission that is rendered inoperable by the locking means (5) has an inner lever ( 70) via a connecting pin (70a), and is of a known structure so as to be operated in the axial direction by the swinging of the inner lever (70), and in the embodiment shown in the figure, the inner lever (70)
A lock plate (71) is integrally formed at the upper end, and the locking means (5) is provided on the -side of the lock plate (71).
), and in the lock plate (71), the lock plate (71) faces the end surface of the lock body (53) of the lock means (5) when the shift lever is operated to the parking range (P) or the neutral range (N). First and second fitting holes (72) into which the lock body (53) fits
(73), and by fitting the lock body (53) into the first or second fitting hole (72) (73), the inner lever (70) swings, in other words, the manual valve (7) is prevented from operating.

The above-mentioned locking means (5), for example, when the automatic transmission is shifted to the neutral range (N), when hydraulic pressure is introduced into the working chamber (56), the piston (54) It moves forward (downward in FIG. 3) against the second spring (58), and as the piston (54) moves forward, the lock body (53) moves through the first spring (57). ) also moves forward, and the lock body (5
The end of the large diameter shaft portion (53b) in 3) protrudes from the valve case (51) and fits into the second fitting hole (73). At this time, if the second fitting hole (7
3) is not located in a position facing the end of the lock body (53), the end of the lock body (53) comes into contact with the side surface of the lock play (71) and moves forward. However, only the piston (54) moves forward, compressing the first spring (57), and the swinging of the inner lever (70) accompanying the operation of the shift lever causes the first spring to move forward. 2 fitting holes (73) are connected to the lock body (53).
At the stage where the lock body (53) faces the end of the lock body (53), the spring force of the first spring (57) moves the large diameter shaft (53b) into the second fitting hole (73). They fit together.

On the other hand, the governor oil pressure detection means (4) is incorporated into the control means (6) for locking the locking means (5), and then this governor oil pressure detection means (4) is incorporated. The control means (6) will be explained.

As shown in FIGS. 5 and 6, this control means (6) has first, second, and third lands (62a) (62b) ( E3
A three-land type spool (62) with a first land (62a) in the spool (62) is installed inside.
), and the spring chamber (S1) is located outside the third land (63c) of the spool (62).
S2) are respectively provided, and the spring chamber (S2),
A coil spring (64) is interposed to bias the spool (62) toward the working chamber (S1).

The diameters of the lands (82a) (62b) (62C) are the same as the second and third lands (62b) (82C), and the first land (62a) is the same diameter as the second land (+3
The diameter is smaller than 2b).

In the working chamber (S1), a governor (
A governor oil passage (41) that guides the governor hydraulic pressure generated in the working chamber (S1) and the spool (6
2) constitutes the governor oil pressure detection means (4), while the first land (62a)
) and the second land (62b), a second control oil passage (L3) extending from the output boat (33) of the range detection means (3) is connected, and the second land (62b) and the second land (62b) are connected to each other. 3 land (82c) and a secondary side passage (L4-1) of the supply oil passage (L4) for introducing line pressure into the working chamber (56) of the locking means (5). Side passage (L4
-2), and a drain oil passage (L5) that is open to the oil pan is connected to the spring chamber (S2).

Further, in the embodiment shown in the figure, an accumulator (8) for temporarily storing the hydraulic oil introduced into the supply oil path (L4) is provided in the valve body (61). Specifically, as shown in FIG. 5, an accumulator chamber (81) is formed in the valve body (61) and communicates between the second and third lands (E32b) (82c) in the accommodation hole (61a). An accumulator piston (82) and a return spring (83) are housed in the accumulator chamber (81).

Therefore, the above accumulator (6) is operated in the lock state (5) when the supply oil passage (L4) is in the lock state (5).
) The pressure of the hydraulic oil introduced from the downstream passage (L4-1) causes the accumulator piston (82) to 1)
The hydraulic fluid is temporarily stored in the accumulator chamber (81) by moving it forward against the turn spring (83) marked I, thereby creating a time lag in the locking operation of the locking means (5). It is meant to make you feel better.

In the control means (6) described above, the spring chamber (
The spring force of the coil spring (64) installed in S2) is such that the governor oil pressure introduced into the working chamber (S1) is
The value is set to be stronger than the oil pressure generated when driving at speeds of 5 km or less, but weaker than the oil pressure generated when driving at speeds of 15 km/h or higher. When the spool (62) always moves forward against the coil spring (64), the second land (Ei2b) connects the supply oil path (L4).
While blocking communication between the downstream passageway (L4-1) and the secondary passageway (L4-2), the secondary passageway (L4-2)
and the accumulator chamber (81) is connected to the drain oil passage (L5).
) is open to the public.

Note that (0) in the figure indicates an orifice.

Next, the operation of the shift lock device for an automatic transmission having the above structure will be explained.

First, when starting, shift the shift lever of the automatic transmission to parking range (P) or neutral range (
N), no hydraulic pressure is introduced into the first human-powered boat (31) of the range detecting means (3).

However, in such a state, the brake pedal is not depressed, or even if the brake pedal is depressed, the brake fluid pressure generated in the mask cylinder (12) is at a value (below the set value) that cannot reliably brake the IF wheels (14). Sometimes, the valve body (22) of the brake detection means (2) moves back in the right direction in FIG. Since the control oil pressure of the first control oil passage (L1) is communicated with the oil pan, the control oil pressure of the first control oil passage (L1) is released to the oil pan, and therefore the first and second lands (62a) of the spool (62) in the control means (6)
(62b) Since neither the working hydraulic pressure nor the control hydraulic pressure is introduced between the working chambers (S
1) The governor hydraulic pressure introduced into the coil spring (
Since the spring force of the coil spring (64) is weaker than the spring force of the coil spring (64), the spool (62) is located at a position where it has moved back by the spring force of the coil spring (64), as shown in FIG.

By locating this spool (62) in the double movement position, the − next side passage (L4-1) of the supply oil passage (L4)
) to the secondary passageway (L4-2) and the accumulator chamber (
81), and the pressure of the hydraulic oil causes the accumulator piston (82) to move forward against the return spring (83).

After a predetermined amount of the hydraulic oil remains in the accumulator chamber (81), the working chamber (5) of the locking means (5)
Hydraulic pressure is supplied to the lock body (6) through the piston (54) and the first spring (57).
53) is the forward movement, and the large diameter shaft part (53b) of the lock body (53) is the first part formed on the lock plate (71) of the first inner lever (70) if the parking range is used. If the neutral range is in the fitting hole (72), the second fitting hole (72) is fitted to prevent the inner lever (70) from swinging. If this is not done reliably, the automatic transmission cannot be shifted from the stop range to the drive range, thereby preventing the vehicle from starting inadvertently.

(Then, when the brake pedal (11) is depressed in such a situation, the brake fluid pressure generated in the mask cylinder (12) reaches the i1 value (which can reliably brake the wheels (14)). (a set value or more), the valve body (22) of the braking detection means (2) moves against the return spring (26) due to the action of the brake fluid pressure.
The control boat (24) is closed by the ball valve (22a) as it moves toward the left in the drawing, and control oil pressure is generated in the first control oil path (L1).

Then, the control oil pressure generated in the first control oil passage (L1) is introduced into the valve chamber (35) via the second capo (32) of the range detection means (3), and the control oil pressure is introduced into the valve chamber (35). acting on the check ball (36) to move the check ball (36) to the left in FIG.
At the same time, the second person capo (32) and the output port (33) are communicated with each other, and accordingly, the control oil pressure is transmitted through the output port (33) and the second control oil path (L3). The control hydraulic pressure is introduced between the first and second lands (62a) (132b) of the spool (62) in the control means (6) and acts on the area difference between the first and second lands (82a) (f32b). , the spool (62) is moved toward the right in FIG. 5 against the coil spring (64).

As the spool (62) moves forward, the second land (62b) connects the downstream passage (L4-1) and the secondary passage (L4-2) of the supply oil path (L4). is blocked, and the secondary side passage (L4-2) and the accumulator chamber (81) communicate with the drain oil passage (L5), and the working chamber (56) of the locking means (5) and the accumulator chamber (81) The control oil pressure in the drain oil path (L5
), whereby the locking body (53) of the locking means (5) moves back due to the spring force of the second spring (58), and the large diameter shaft portion (53b) is opened to the locking brake (71). The illumination groove (72) or the second fitting hole (7
3) and releases the lock of the inner lever (70), so that from now on it is possible to shift the automatic transmission to any range.

By the way, for example, during high-speed driving, the governor hydraulic pressure introduced into the working chamber (S1) flows into the spring chamber (S1).
Since the spring force is higher than the spring force of the coil spring (64) in S2), the spool (62) always moves forward against the coil spring (64) under the action of the governor hydraulic pressure, so that 1) II As mentioned above, the supply oil path (L4)
Secondary passageway (L4-2) and accumulator chamber (81
) is open to the drain oil passage (L5), so the inner lever (70) will not be locked. Therefore, the automatic transmission can be accidentally switched from the drive range (D) to the neutral range during high-speed driving. (N), the automatic transmission can be immediately returned to the drive range (D), for example, without having to perform a brake operation each time like when starting.

On the other hand, when the automatic transmission is shifted to one of the drive range (D), second range (II), and low range (L), the first manual boat (31) of the range detection means (3) Hydraulic pressure is introduced into the valve chamber (35) through the valve chamber (35), and the check ball (36) moves to the right in FIG.
) and the output port (33) communicate with each other, and the hydraulic pressure is applied to the eleventh spool (62) in the control means (6) via the output port (33) and the second control oil passage (L3).
Introduced between the second lands (62a) (62b), the first land,
Due to the hydraulic pressure acting on the area difference between the second lands (82a) and (62b), the spool (62) moves toward the right in FIG. 5 against the coil spring (64).

As the spool (62) moves forward, the second land (82b) connects the downstream passage (L4-1) and the secondary passage (L4-2) of the supply oil path (L4). is blocked and the secondary side passage (L4-2) and the accumulator chamber (81) are opened to the 1lif drain oil passage (L5), so the working chamber (56) of the locking means (5) is No hydraulic pressure is introduced and the locking means (5) remains unlocked.

Therefore, when the automatic transmission is in the drive range (D), second range (n), or low range (L), it is possible to freely shift the automatic transmission to other ranges.

By the way, in the above embodiment, when the automatic transmission is shifted to the reverse range (R), the brake reaches a value (m) that cannot reliably brake the wheels (14), similar to when the automatic transmission is shifted to the parking range. (below a fixed value),
The hydraulic pressure is introduced into the working chamber (56) of the locking means (5), and the locking body (53) moves forward, but the blood transfusion in the locking body (53) does not reach the side of the locking plate (71). Just by making contact, the inner lever (70) will not be locked, and therefore it is possible to freely shift from Reverse Lenz (R) to other ranges.

On the other hand, when the vehicle is parked in a garage or parallel parked, the automatic transmission is switched from drive range (D) to reverse range (R).
), and then switch from the perspective range (R) to the drive range (D) and select i1? When repeating forward movement and reverse movement, the sleeve (62) of the control means (6) passes through the neutral range (N) each time, and each time the sleeve (62) of the control means (6) The next passage (L) of the supply oil passage (L4) is
4-1) communicates with the secondary passageway (L4-2).

However, as described above, even if the downstream passage (L4-1) of the supply oil passage (L4) is connected to the secondary passage (L4-2), due to the action of the accumulator (8), Since the automatic transmission is switched from the neutral range to another range before the hydraulic pressure is applied to the working chamber (56) of the locking means (5), the neutral range (N
) There is no need to operate the brake each time the vehicle passes, so it is possible to smoothly park the vehicle in a garage or parallel park.

In the above embodiment, the dry plane 7 (D
), a second range (II), and a range detection means (3) configured to input switching hydraulic pressure to a low range (L) as detection signals to detect the shifted range of the automatic transmission. However, a range detection means (3) may be provided which detects the range in which the automatic transmission is being shifted, for example by electrically detecting the operating position of the shift lever.

Further, in the above embodiment, a locking means (5) operated by the line pressure of the automatic transmission is provided, but a locking means operated by, for example, energization of an electromagnetic solenoid may be provided.

Further, in the braking detection means (2) of the above embodiment,
The brake fluid pressure generated in the brake device (1) is detected to determine whether or not the brake is applied from the brake fluid pressure. For example, the operation of the brake device is detected from the on/off operation of a brake lamp switch. You may also do so.

(Effects of the Invention) As described above, the present invention provides a hydraulically operated automatic transmission having a stop range and a travel range, including a range detection means for detecting the range and a braking detection means for detecting the operation of a brake device. and a governor oil pressure detection means for detecting the governor oil pressure generated in the governor of the automatic transmission; and based on the detection results by each of the detection means, when the automatic transmission is shifted to the stop range, the governor oil pressure is determined to be at a predetermined level. and a locking means that disables shifting of the automatic transmission using the line hydraulic pressure of the automatic transmission as the operating source when the brake system is not operating. If the brake system is not operating when the governor oil pressure is below a predetermined value, such as when starting, the shift of the automatic transmission is locked and the vehicle is suddenly shifted to an unused position. On the other hand, when the vehicle is in motion and the governor oil pressure is above a predetermined value, even if the automatic transmission is shifted from the drive range to the stop range by mistake. , the shift of the automatic transmission will not be locked. Therefore, if you accidentally shift the automatic transmission from the drive range to the neutral range while driving at high speed, you will not need to apply the brake each time as you would when starting. In both cases, the automatic transmission can be immediately returned to the driving range.

[Brief explanation of the drawing]

FIG. 1 is a schematic explanatory diagram showing one embodiment of a locking device for an automatic transmission according to the present invention, FIG. 2 is a sectional view of the brake detection means, FIG. 3 is a sectional view of the main part of the locking means, and FIG. The figure is a schematic perspective view of the locking means, FIG. 5 is a cross-sectional view of the control means, and FIG. 6 is a cross-sectional view taken along the line ■--■ in FIG. (2)...Braking detection means (3)...
... Range detection means (4) ... Governor oil pressure detection means (5) ...
... Locking means (6) ... Control means Applicant: Daihatsu Motor Co., Ltd., 2. . ``0 raco watch tako ward ■ law mokuku right

Claims (1)

[Claims] 1) In a hydraulically operated automatic transmission equipped with a stop range and a travel range, the range detection means for detecting the range, the braking detection means for detecting the operation of the brake device, and the governor of the automatic transmission generate Based on the governor oil pressure detection means that detects the governor oil pressure and the detection results by the respective detection means, when the automatic transmission is shifted to the stop range, the governor oil pressure is below a predetermined value and the brake device is not operating. 1. A shift lock device for an automatic transmission, comprising: locking means that uses the line hydraulic pressure of the automatic transmission as an operating source to disable shifting of the automatic transmission when the automatic transmission is not in use.