JPH0117714Y2 - - Google Patents

Description

[Detailed description of the invention] (Technical field) This invention relates to the improvement of a power shift type auxiliary transmission that is installed in the power transmission system of large vehicles such as trucks and switches the gear stage of the main transmission between high and low. .

(Background Art) This type of sub-transmission is configured as shown in FIG. 1, for example.

1 is the auxiliary transmission body with high gear and low gear,
Reference numeral 2 denotes an air cylinder for performing the shift operation, and its interior is defined by a piston 3 into two chambers 4 and 5.

The two chambers 4 and 5 are connected to an air reservoir tank 8 via air passages 6 and 7, respectively, and magnetic valves (three-way solenoid valves) 9 and 10 are interposed in these air passages 6 and 7, respectively.

Each of the magnetic valves 9 and 10 communicates the passage on the reservoir tank 8 side with the passage on the air cylinder 2 side when energized, while blocking the passage on the reservoir tank 8 side and opens the passage on the air cylinder 2 side to the atmosphere when not energized. open to

The electric circuit of magnetic valves 9 and 10 includes:
A manual changeover switch 13 for selectively switching the energization of the magnetic valves 9 and 10 is interposed in series with a clutch pedal switch 12 that is turned ON when the clutch pedal 11 is depressed.

Micro switches 14 and 15 are provided on the ground sides of the magnetic valves 9 and 10, respectively.

Among these, the micro switch 15 is in the illustrated state (when the air cylinder 2 is contracted), and the push rod 17 is lowered to the small diameter portion 19 of the piston rod 18, and the other micro switch 14 is OFF. The push rod 16 is pushed up and turned ON, but when the piston rod 18 extends from this state, the micro switch 15 is turned ON as the push rod 17 rides on the large diameter part 20 at the fully extended position, and at the same time, the micro switch 14 turns the piston rod 18 It descends to the small diameter part 21 of the pipe and turns OFF.

22 is a pilot lamp that lights up when micro switch 14 is turned on, 23 is micro switch 1
5 indicates the pilot lamp that lights up when turned on, and 30 indicates the fuse box.

Then, in the state shown in the figure, depress the clutch pedal 11 (thereby, the clutch pedal switch 12
When the changeover switch 13 is turned to the low side (ON), the magnetic valve 9 is energized and the air pressure from the air reservoir tank 8 is supplied to the chamber 4 of the air cylinder 2.

At this time, the other magnetic valve 10 is de-energized and blocks the passage on the reservoir tank 8 side.
The chamber 5 of the air cylinder 2 is opened to the atmosphere.

Therefore, the air cylinder 2 is pushed by the air pressure supplied to the chamber 4, and the piston 3 slides in the direction of the arrow.
Shift fork 24 with integrated piston rod 18
, the gear of the sub-transmission main body 1 is switched from high gear to low gear.

At the same time, when the piston rod 18 is fully extended, the micro switch 14
descends into the small diameter portion 21 of the piston rod 18.
The power is turned OFF, cutting off the power to the magnetic valve 9 and turning off the pilot lamp 22.

On the other hand, the micro switch 15 has a push rod 17 in the large diameter portion 20 due to the extension of the piston rod 18.
boarded and turned on, pilot lamp 23
lights up.

Then, after confirming that the pilot lamp 23 has been turned on to confirm switching to low gear, the clutch pedal 11
All you have to do is tell the story and inherit the clutches.

In order to change from low gear to high gear, the selector switch 13 can be manually switched to the high side in the same manner as described above. In this case, the magnetic valves 9 and 10, the air cylinder 2, and the micro switches 14 and 15 are The gear is changed by the reverse operation, and the pilot lamp 22 indicates the high gear operation.

Furthermore, in order to prevent damage to the periodic device due to faulty clutch disengagement, Utility Application No. 58-108278 states that a relay switch is installed that cuts off the current if the electric circuit of the magnetic valve continues to be energized for a certain period of time or more. has been proposed.

By the way, in such an auxiliary transmission, the manual changeover switch 13 is disposed near the shift lever 25 of the main transmission, as shown in FIGS.
For example, if you want to shift sequentially from 1st gear low to 6th gear high in this case, in 1st gear low, depress the clutch pedal 11 to switch the selector switch 13 from low to high, shift to 1st gear high, then clutch pedal 11. is pressed to return the changeover switch 13 to low, and the shift lever 25 is put into 2nd gear to go to 2nd gear low, and then in the same manner up to 6th gear high, and the shift operation is repeated.

In other words, during a 12-speed shift, selector switch 13 is set to 12
It is necessary to switch the shift lever 25 six times and depress the clutch pedal 11 each time.
Shifting operations were extremely complicated.

On the other hand, in Japanese Patent Application Laid-open No. 55-76244,
It detects the vehicle speed or engine speed during gear shifting of a manual transmission equipped with an auxiliary transmission, and controls switching of the auxiliary transmission according to the optimum shift diagram set in advance for each gear. A control method is disclosed.

However, in order to achieve the purpose of controlling the auxiliary transmission with speed change characteristics depending on the situation, this control method requires an MPU (CPU) as the center, as described as an example in the same publication. This method requires the use of an expensive and complicated microcomputer system, which makes it difficult to apply it to industrial vehicles, etc., which have strict cost requirements.
Also, whenever the shifting characteristics change depending on the vehicle speed or engine speed, there is a limit to the capacity or type of shifting diagram that can be set in advance.
There was also the problem that the speed change control was not necessarily performed as desired by the driver.

The present invention was developed with a focus on these problems, and it is a power shift type sub-transmission that has a simple structure, can automatically switch between low and high levels of the sub-transmission, is inexpensive, and has a high degree of operational freedom. is intended to provide.

(Structure of the invention) In order to achieve the above object, the present invention provides a power shift type auxiliary transmission that further switches the gear stage of the main transmission between high and low gears. The switch circuit of the magnetic valve installed in each of the high side and low side air passages that communicate with the A selector switch for switching between high and high is provided in parallel, and a selection switch is also provided for selectively switching the circuit on the rotary switch side or the selector switch side.

(Operation of the invention) According to the above structure, the rotary switch alternately switches between the low side and the high side in conjunction with depression of the clutch pedal, thereby automatically changing the speed of the sub-transmission. Therefore, although the structure is simple, the driver can be freed from complicated gear shifting operations of the sub-transmission.

In addition, by operating the selection switch, the circuit is switched to the manual transfer switch located in parallel with the rotary switch, so it is also possible to freely operate the sub-transmission manually according to the driver's will. .

(Example) This invention will be explained below according to the example shown in FIGS. 4 and 5. Note that the same parts as in FIGS. 1 to 3 are denoted by the same reference numerals.

Reference numeral 1 denotes the sub-transmission main body, 2 an air cylinder for performing the shift operation, and 9 and 10 interposed in air passages 6 and 7 that respectively connect the two chambers 4 and 5 of the air cylinder 2 to the air reservoir tank 8. A magnetic valve is shown.

The electric circuit of magnetic valves 9 and 10 includes:
A rotary switch 26 which alternately switches between low and high in conjunction with depression of the clutch pedal 11 is interposed between the clutch pedal switch 12 and the magnetic valves 9 and 10, in this case in parallel with the changeover switch 13.

27 is a selection switch that switches the circuit between the changeover switch 13 side and the rotary switch 26 side.

In addition, manual changeover switch 13 and selection switch 2
7 is arranged on the steering handle 28 as shown in FIG.

Therefore, when the selection switch 27 is set to the auto side and the clutch pedal 11 is depressed in the state shown, the rotary switch 26 is automatically switched from high to low in conjunction with this, and the magnetic valve 9 is energized. Ru.

As before, the magnetic valve 9 supplies air pressure from the air reservoir tank 8 to the chamber 4 of the air cylinder 2, while the other magnetic valve 10 is de-energized and supplies the air pressure from the air reservoir tank 8 to the chamber 4 of the air cylinder 2.
Release the air pressure to the atmosphere.

As a result, the air cylinder 2 switches the gear of the sub-transmission main body 1 from the high gear to the low gear via the shift fork 24 due to the extension of the piston rod 18.

At the same time, when the piston rod 18 is fully extended, the micro switch 14 is turned off, cutting off the power to the magnetic valve 9 and extinguishing the pilot lamp 22.
It turns on and the pilot lamp 23 lights up.

Then, after confirming that the pilot lamp 23 has been turned on to confirm switching to low gear, the clutch pedal 11
All you have to do is let go.

When the clutch pedal 11 is next depressed, the rotary switch 26 is switched to the high side, and the magnetic valve 10 is energized, contrary to the above, and the air cylinder 2
Due to the contraction, the gear of the sub-transmission main body 1 is switched from a low gear to a high gear, and the pilot lamp 23 is turned off by the operation of the micro switches 14 and 15, and the pilot lamp 22 is turned on instead.

By the way, since the rotary switch 26 is linked to the depression of the clutch pedal 11 and automatically switches between low and high, there is no need to manually switch the switch 13 every time the gear is changed, as is the case in the past. , Therefore, the shift operation at the time of gear change becomes easy.

In the above embodiment, the manual changeover switch 13 is
, and use selection switch 27 to turn rotary switch 2.
6 and manual changeover switch 13, the manual changeover switch 13 can be used to change the gear of the sub-transmission main body 1 to low gear,
Alternatively, it is also possible to manually shift to a high gear.
For this reason, if a driving situation is encountered in which it is not desirable for the auxiliary transmission to automatically shift gears by operating the rotary switch 26 in response to the depression of the clutch pedal, or if the driver's preference Appropriate driving force can be exerted.

(Effects of the invention) In short, according to this invention, a rotary switch is provided in the electric circuit of the magnetic valve that alternately switches between low and high in conjunction with depression of the clutch pedal, so the switch can be manually operated when changing gears. There is no need to perform a switching operation, which facilitates shift operations when changing gears.

In addition, in this invention, a manual changeover switch installed in parallel with the rotary switch can be selected by operating a selection switch, so the sub-transmission can be manually shifted according to the driving situation or the driver's will. ,Therefore, there is a high degree of freedom in shifting operations,
It can respond to various driving situations.

Furthermore, the present invention has a relatively simple structure in which the auxiliary transmission is automatically shifted by a rotary switch that is linked to a clutch pedal, so it has the advantage that it can be realized at low cost.

[Brief explanation of the drawing]

Figure 1 is a schematic configuration diagram of the conventional device, Figures 2 and 3 are diagrams showing how the changeover switch is installed, Figure 4 is a schematic configuration diagram showing an embodiment of this invention, and Figure 5 is how the changeover switch is installed. It is a diagram. 1...Sub-transmission body, 2...Air cylinder,
6, 7... Air passage, 8... Air reservoir tank, 9, 10... Magnetic valve, 11...
Clutch pedal, 26...Rotary switch, 2
7...Selection switch.

Claims (1)

[Scope of utility model registration request] In a power shift type auxiliary transmission that further switches the gear stage of the main transmission between high and low, the air passages are installed in the high-side and low-side air passages that connect both chambers of the cylinder that performs the shift operation to the air reservoir tank, respectively. A rotary switch that alternately switches between low and high in response to depression of the clutch pedal, and a changeover switch that switches between low and high by manual operation are provided in parallel in the switch circuit of the magnetic valve. A power shift type sub-transmission characterized by being provided with a selection switch that selectively switches between a side circuit or a changeover switch side circuit.