JPS6177527A - 4-wheel driving car - Google Patents

Abstract

PURPOSE:To certainly obviate the tight corner braking phenomenon by correctly detecting the tight corner turn by the difference of revolution between the right and left wheels of selection driving wheels. CONSTITUTION:Rear wheels 12 are connected through a rear driving shaft 23, rear differential gear 24, and a rear axle 25, and front wheels 11 are switched between drive and non-drive by the operation of a 2-4 wheel drive selecting clutch 15, and rear wheels 12 are directly driven by the output supplied from a transmission mechanism 14. The clutch 15 is switching-controlled by a controller 26, into which the signals of the pick-up sensors 26 and 27 for detecting each number of revolution of the right and left front axles 22 are input. The electric signal of a sensor 27 is converted to the selection signal representing each number of revolution of the right and left wheels 16R and 16L, and the difference of the number of revolution is calculated, and when the difference is over a prescribed value (alpha), turning in tight corner is judged.

Description

Detailed Description of the Invention (Field of Industrial Application) This invention provides a method for switching clutches between two-wheel drive, which drives one of the front and rear wheels, and four-wheel drive, which drives both front and rear wheels. Regarding the 4-wheel drive vehicle that can be switched by Okasaku, in more detail, it is a 4-wheel drive J vehicle that can avoid the phenomenon of tight-1-nave braking that occurs when turning when driving in 4-wheel drive. lyl.

(Conventional technique) As a means to avoid the above-mentioned tight corner braking phenomenon, conventionally, a center differential was installed at an intermediate position between the front and rear wheel drive systems; There is a method of absorbing this by using a method, but this method has the problem of complicating the structure and increasing the weight of the vehicle.

Another method is to interpose a clutch in the rear wheel drive system, detect tight corner turns using a steering angle sensor, and operate the clutch described above to control the rear wheel drive power transmission component. A method of reducing and absorbing the amount (for example, JP-A-58-20
However, in this case, the turning state detected by the steering angle sensor does not necessarily match the actual turning state of the vehicle, so clutch control is not performed even though the turning is in a tight corner. malfunction,
Another problem is that the clutch is erroneously operated when turning a corner that is not a tight corner.

(Objective of the Invention) The object of the present invention is to detect the difference in rotational speed between the left and right wheels of the front and rear wheels that are switched to driving and non-driving, and to switch to two-wheel drive. To provide a four-wheel drive vehicle that can reliably detect tight corner turning and reliably avoid tight corner braking.

(Structure of the Invention) This invention detects the rotational speed of the left and right wheels of J5 on the side that is switched to drive/non-drive among the front and rear wheels, and detects the difference between the two rotational speeds. Whether the difference is greater than or equal to the specified value:
In response to a detection signal from the rotation speed detection means that detects the engine speed, if the difference between the rotation speeds of the left and right wheels exceeds a predetermined value, the system switches to two-wheel drive.
The vehicle in which the difference is less than a predetermined value is characterized in that the vehicle is a four-wheel drive vehicle in which the control means uses an intermittent control i20 to switch between two-wheel drive and four-wheel drive.

That is, as shown in FIG. 1, the moe/rear wheel 10 has a switching drive wheel 11 that can be switched between driving and non-driving.
and a direct drive wheel 12 to which driving force is directly transmitted, and the direct drive wheel 12 is a transmission gear 4 connected to an engine 13.
The output from the iiS 14 is directly transmitted, and the output is transmitted to the switching drive wheel 11 via the 2-4 wheel drive switching clutch 15. , a rotation speed detection means 17 for detecting the difference between the two rotation speeds is provided, and this rotation speed detection means 1
The control means 18 controls the control means 18 so that when the detection signal 7 indicates that the rotational speed light of the left and right wheels 16 is above a predetermined value, the drive is set to two-wheel drive, and when the difference is less than a predetermined value, the drive is set to four-wheel drive. J is characterized in that the vehicle is a four-wheel drive vehicle in which the clutch for switching between two-wheel drive and four-wheel drive is controlled on and off.

(Effects of the Invention) As described above, this invention detects a turn in a tight corner based on the rotation difference between the left and right wheels of the switching drive wheels. The signal causes the vehicle to switch to two-wheel drive when turning in tight corners, thereby reliably avoiding the phenomenon of tight corner braking.

Furthermore, by detecting the difference in rotation between the left and right wheels of the switching drive wheel, since the left and right wheels are rotated by the ground pressure when not being driven, accurate rotation speed can be detected and tight corners can be handled easily. When returning to wheel drive, it is operated quickly, allowing smooth return to four-wheel drive.

Moreover, when a differential lock is installed on the directly driven wheels, if the directly driven wheels are used to detect the rotational speed of the left and right wheels, the rotational speed of the left and right wheels cannot be detected when the differential is locked. 1) When the rotation speed is detected on the driving wheel side, the rotation speed of the left and right wheels can be detected without being interfered with by the differential lock.

(Example) An embodiment of the present invention will be described in detail below based on the drawings.

The drawing shows a four-wheel drive vehicle, and in FIG.
3 output is transmission machine groove (transmission) 14
In this mission Bl, t.

14 is manually supplied to a transformer 7719, and this transfer 19 is provided with a clutch 15 for switching between two-wheel drive and four-wheel drive.

The drive wheels include a front wheel 11 as a switching drive wheel that can be switched between drive and emergency drive, and a rear wheel 12 as a direct drive wheel.
1 is front drive than 11 transformers! lll1ll
+ 20, front differential 21, front axle 22.22
The rear wheels 12 are connected via the rear drive shaft 23, the A7 differential 24, and the X7 car @25.25, and the front wheels 11 are connected via the 2-4 wheel drive switching clutch 15 described in 114. Operation 1' is used to switch between drive and non-drive, and the rear wheel 1
2 is directly driven by the output from the mission (1°1114).

The above-mentioned 2-4 wheel drive VJ switching clutch 15 is switched and controlled by a controller 26.
Signals from pickup sensors 27, 27 that detect the rotational speed of the left and right front wheels 1t22, 22 of the front wheels 11 are input to 6.

The above-mentioned controller 26 is constituted by a well-known microcomputer, and the above-mentioned pickup sensor 27.2
The electrical signals of 7 are converted into detection signals indicating the rotation speeds of the left and right wheels 16L and 16R, and the difference between the respective rotation speeds is calculated.
When this rotational difference is greater than or equal to the predetermined value α, it is determined that the turning is in a tight corner.

The above-mentioned predetermined value α is set, for example, to a rotation difference of 70% to 80% of the rotation difference that occurs at the minimum turning radius of the vehicle.

FIG. 3 shows the aforementioned transfer 19, with input +1 and 3.
1 and the output shaft 32 are arranged coaxially and separately, and the input shaft 31 is provided with a low speed clutch 33 and a high speed clutch 34, and the output side of the high speed clutch 34 is connected to the output i1'.
It is formed on the inner surface of the input gear 35 connected to the inner shaft end of the 1l132, and this high-speed clutch 34 is ON i=
By being sr, the output of the input rld+ 31 is directly delivered to the output shaft 32.

An output key 1736 is provided on the output side of the aforementioned low speed clutch 33.
is formed and is supported on the shaft of the input shaft 31 via a bearing, and this output key 1736 is engaged with the input side 37 of the reduction gear 37.38, and its output side 389 is connected to the input key 1- 35 meshes, and reduction gears 37 and 38 are case 3.
It is rotatably supported via a bearing on a support shaft 40 installed at 9.

The above-mentioned output shaft 32 is equipped with a clutch 1 for switching between 2-4 wheel drive.
An output sprocket 41 for the front drive IJ+ is formed on the output side of the clutch 15, and is supported by 1 pJi on the ° axis of the output IP II 32 via a bearing.

An input subblock 42 for front drive is pivotally supported in the lower part of the case 39 via a support, and a chain 43 is stretched between the input subblock 42 and the output subblock 41 described above.

According to the drive system described above, when the low speed clutch 33 is turned on f
'l''T, the human power is transferred to the output gear 36 and the reduction gear t.
37.38, the output shaft 32 is driven via the input gear 35, and when the high-speed clutch 34 is turned on, the output shaft 32 is directly driven.

When the 2-4 wheel drive switching clutch 15 is turned on, the driving force of the output shaft 32 drives the input sprocket 42 via the output sprocket 41 and the chain 43.

A flange 44 fixed to the outer end of the output shaft 32 is connected to the above-mentioned V drive@23 to drive the rear wheel 12, and a flange 45 connected to the output side of the input cast brocket 42 is connected to the front The front wheel 11 is connected to the drive shaft 20.
to drive.

A pressure regulator valve 46, a manual valve 47, and a shift valve 48 are installed in the upper part of the case 39 mentioned above.
is set up.

Above) Small Blessi A? The regulator valve 4G controls the pump discharge pressure of the hydraulic pump 49 provided on the input side of the input 10% 31 to a constant pressure.

Further, the manual valve 47 performs a switching operation between auto and manual by operating the operating lever 50 by the driver, and in conjunction with this, the clutch 15 for 2-4 wheel drive switching is operated to switch between 2-wheel drive and 4-wheel drive. Can be switched to wheel drive.

In addition, when the solenoid valve 51 is operated by the shift valve 48 (the above-mentioned controller 26), the clutch 15 for switching between 2-wheel drive and 4-wheel drive is operated.
Can be switched to wheel drive.

The oil passage 52 from the shift valve 48 is connected to the back side of the screw 1-53 of the 2-4 wheel drive VJ exchange clutch 15, and the piston 53 is moved by supplying pressure oil to this mechanism. It moves and the clutch is turned on.

Note that the low-speed and high-speed clutches 33 and 34 described above are constructed in the same manner.

FIG. 4 shows the operating position of the operating lever 50 described in 110, where A is the auto position, and 2-4 wheel drive switching is automatically performed. In this case, the high speed clutch 34 is turned ON and the /1 wheel drive is set to only 1 high speed drive.

B, C, and D are the driver's manual operation positions, and C position is the two-wheel drive operation position, and the 2-4
The wheel drive switching clutch 15 is operated OFF. C
The position is the high-speed four-wheel drive position, and the high-speed clutch 3
4.2-4 wheel drive switching clutch 15 is operated to ON. The C position is a low-speed four-wheel drive position, and the low-speed clutch 33.2-four-wheel drive switching clutch 15 is ON.
Be manipulated.

Note that each operating position of the above-mentioned operating lever 50 is detected by an appropriate sensor.

The operation of switching between 2-wheel drive and 4-wheel drive in the 4-wheel drive vehicle configured as described above will be explained with reference to FIG. In this embodiment, when the operating lever 50 is in the auto position, four-wheel drive is automatically controlled to increase the grip force of the wheels when starting or when the wheels slip.

In a first step 61, it is determined whether or not the operating lever 50 is in the auto position A based on the output of a sensor (not shown) provided on the operating lever 50, and when it is determined that it is in the auto position faA, At the second step 62, the vehicle starts u,
This determination is made by detecting the driving state of the vehicle, and if it is determined that the vehicle is not in the starting state, it is determined in a third step 63 that the Q1 wheel is slipping. In other words, the rear wheel 12's V vehicle 'tTl 12b, 25 is provided with a pickup sensor (not shown) that detects this rotation speed, and calculates the rotation speed of the front and rear wheels to detect the rotation speed of the bamboo wheel 11.
The rotational speed of the rear wheel 12 and the rear wheel 12 are compared to detect the slip state of the wheel.

If it is determined that the wheels are not slipping, the process proceeds to the following steps, and braking phenomenon avoidance processing for the tie 1 corner is performed.

That is, 4th. 5th step knob 64.65, front wheel 1
Rotation speed NL of left and right wheels 16L and 16R of 1.

NR is detected based on the output of the pickup sensor 27.27, and in a sixth step 66, the difference between the above-mentioned two rotational speeds NL and NR is determined, and it is determined whether the difference between the rotational speeds is larger than the above-mentioned predetermined value α. If it is determined to be smaller, it is determined that it is not a tight dog turn, and in the seventh step 67, the solenoid valve 51 of the shift valve 48 is turned on, and the 2-4 wheel drive switching clutch 1 is turned on.
5 is turned on, and both the front wheels 11 and the rear wheels 12 are driven.

When it is determined in the above-mentioned sixth step 66 that the turning is larger than the predetermined value α, it is determined that the turn is a tight turn, and in the eighth step 68, the solenoid valve 51 of the shift valve 48 is turned off. Then, the 2-4 wheel drive switching clutch 15 is turned off, so that only the rear wheels 12 are driven and the front wheels 11 are not driven.

As a result, the phenomenon of tight corner braking is avoided.

When it is determined in the first step 61 that the operating lever 50 is not in the oar position, the ninth step 69
Then, it is determined whether the operating lever 50 is in the 4-wheel drive position C or D, and when the 4-wheel drive is determined, the process skips to the fourth step 64 and performs braking phenomenon avoidance processing for tight corners as described above. will be carried out.゛If the four-wheel drive positions C and D are not determined in step 69 above, it is two-wheel drive, so the eighth step 68
will be skipped to.

When it is determined in the second step 62 that the vehicle is not starting (while the vehicle is running), or if a slip is detected in the third step 63, the process skips to the seventh step 67.
Turn on the solenoid valve 51.

The vehicle enters four-wheel drive mode.

As in the above embodiment, the left and right wheels 16L, 16 of the front wheel 11
Detects the rotation difference between R and detects turning in a tight corner.
By switching to two-wheel drive, tight corner braking ``11'' can be reliably performed.

In the correspondence between the configurations of this invention and the embodiments described above, the rotation speed detection means of the invention is similar to the pickup sensor 2 of the embodiments.
7.27 and the processing of the fourth to sixth steps 64 to 66, and the control means corresponds to the shift valve 48 and the processing of the sixth to eighth steps 66 to 68. Corresponds to the same part name.

[Brief explanation of drawings]

The drawings show an embodiment of the invention, and FIG. 1 shows an embodiment of the invention. 2 is a configuration diagram of the four-wheel drive 1FIJ vehicle of the embodiment, FIG. 3 is a front view of the transfer, FIG. 4 is a plan view of the operating lever, and FIG. 5 is a flowchart. 10...Front/rear wheels 11...Switchable drive wheels (front wheels) 12...Direct drive wheels (rear wheels) 13...Engine 14...Mission enclosure 15...2-4 wheel drive Switching clutch 16.16L
, 16R... Left and right wheels 17... Rotation speed detection means 18... Control means 26.
・・Controller 27・・Pickup sensor 10・・Rib Xi combination Fig. 4 Fig. 5

Claims (1)

[Claims] 1. The output from the transmission mechanism connected to the engine is directly transmitted to one of the front and rear wheels, and the output is transmitted to the other of the front and rear wheels via a 2-4 wheel drive switching clutch. A four-wheel drive vehicle configured to transmit transmission, which detects the rotational speed of the other front and rear wheels, and detects the difference between the two rotational speeds, and whether this difference is greater than or equal to a predetermined value or less than a predetermined value. a rotation speed detection means for detecting whether the rotation speed is high and outputting a detection signal; a four-wheel drive vehicle, comprising: a control means for controlling the 2-4 wheel drive switching clutch to engage and engage so that the 2-4 wheel drive switching clutch is switched to 4-wheel drive when the is less than a predetermined value.