Emergency braking system for tractor trailer

Abstract

The application relates to an emergency braking system for a tractor trailer, belonging to the field of tractors. The emergency braking system comprises a first pressure switch, an electromagnetic valve, a reversing valve and a manual pump; the first pressure switch, the electromagnetic valve and the reversing valve are all communicated with a starting oil pipe, the first pressure switch is electrically connected with the electromagnetic valve and is used for driving the electromagnetic valve to reverse, the electromagnetic valve is communicated with the reversing valve and is used for driving the reversing valve to reverse, the electromagnetic valve is communicated with an oil tank, the reversing valve is communicated with a brake oil pipe, an accumulator, a trailer parking brake cavity and a trailer service brake cavity, and is used for braking or releasing the braking of the trailer, the reversing valve, the manual pump and the accumulator are sequentially communicated in one direction, and are used for manually releasing the braking of the trailer. The application is favorable for realizing the emergency braking function of the trailer whether the trailer is towed by a tractor or not, and is favorable for quickly releasing the braking when the trailer is not towed by a tractor.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of tractors, in particular to an emergency braking system for a tractor trailer. BACKGROUND

[0002] Transportation is one of the important functions of a tractor, and the transportation function of the tractor can be realized by connecting a trailer behind the tractor. After the tractor is connected with the trailer, the overall weight increases, so the braking force required by the tractor during braking is also larger. If the tractor relies solely on braking, there is a risk of not being able to stop the vehicle, which may cause the tractor to tip over and pose a great safety hazard. For safety reasons, when the tractor connected with the trailer is braking, both the tractor and the trailer need to have braking functions, so it is necessary to develop a set of trailer emergency braking system for the trailer. However, the existing hydraulic trailer cannot realize trailer emergency braking when there is no tractor for traction, and when the trailer is braked by external hydraulic equipment, the trailer cannot be unbraked when there is no tractor and the trailer needs to move. SUMMARY

[0003] The technical problem to be solved by the present application is to provide an emergency braking system for a tractor trailer to solve the above problems.

[0004] The technical scheme for solving the above technical problem is as follows: an emergency braking system for a tractor trailer, comprising: a first pressure switch, an electromagnetic valve, a reversing valve and a hand pump; the first pressure switch, the electromagnetic valve and the reversing valve are all in communication with a starting oil pipe, the first pressure switch is electrically connected with the electromagnetic valve for driving the electromagnetic valve to reverse, the electromagnetic valve is in communication with the reversing valve for driving the reversing valve to reverse, the electromagnetic valve is in communication with an oil tank, the reversing valve is in communication with a brake oil pipe, an accumulator, a trailer parking brake cavity and a trailer service brake cavity for braking or unbraking the trailer, the reversing valve, the hand pump and the accumulator are in one-way communication in sequence for manually unbraking the trailer.

[0005] The beneficial effects of the present application are as follows: the first pressure switch and the electromagnetic valve are beneficial to reversing the reversing valve under the hydraulic drive of the starting oil pipe, so that the hydraulic oil in the starting oil pipe enters different working valve cores of the reversing valve, and the different working valve cores of the reversing valve are in communication with the brake oil pipe, the accumulator, the trailer parking brake cavity and the trailer service brake cavity, which is beneficial to realizing the emergency braking function of the trailer whether or not the tractor is for traction, and the hand pump cooperates with the reversing valve, the accumulator and the trailer service brake cavity, which is beneficial to quickly realizing unbraking when there is no tractor for traction.

[0006] On the basis of the above technical scheme, the present application can also be improved as follows.

[0007] Further, the electromagnetic valve is a two-position three-way electromagnetic valve, the starting oil pipe drives the first pressure switch to switch, so that the electromagnetic valve is powered to switch, and the electromagnetic valve is switched from the lower position in the initial state to the upper position, and the lower position of the electromagnetic valve is provided with the first check valve.

[0008] The beneficial effect of the further scheme is that the starting oil pipe is communicated with the first pressure switch, which is conducive to making the contacts of the first pressure switch connected under hydraulic pressure, so that the electromagnetic valve is powered to switch, and the hydraulic oil in the starting oil pipe enters the pilot chamber of the reversing valve through the upper position of the electromagnetic valve.

[0009] Further, the reversing valve is a three-position five-way reversing valve, the starting oil pipe is communicated with the pilot chamber of the reversing valve through the upper position of the electromagnetic valve, and the reversing valve is switched from the right position in the initial state to the left position, the left position or the right position of the reversing valve is communicated with the starting oil pipe, and the pilot chamber is communicated with the oil tank through the lower position of the electromagnetic valve.

[0010] The beneficial effect of the further scheme is that the starting oil pipe is communicated with the pilot chamber of the reversing valve through the upper position of the electromagnetic valve, which is conducive to inputting the hydraulic oil in the starting oil pipe into the pilot chamber of the reversing valve, so that the reversing valve is switched from the right position in the initial state to the left position, the left position or the right position of the reversing valve is communicated with the starting oil pipe, which is conducive to realizing the braking or unbraking of the trailer when the trailer is not pulled by the tractor, in cooperation with the brake oil pipe, the accumulator, the trailer parking brake chamber and the trailer service brake chamber, and the pilot chamber is communicated with the oil tank through the lower position of the electromagnetic valve, which is conducive to returning the hydraulic oil in the pilot chamber to the oil tank when the tractor is separated from the trailer (i.e. the starting oil pipe no longer inputs hydraulic oil), so that the reversing valve returns to the initial position.

[0011] Further, the left position first passage, the left position second passage and the left position third passage are arranged in the left position spool of the reversing valve, the left position first passage and the left position second passage penetrate the left position spool of the reversing valve, one end of the left position third passage is communicated with the left position second passage, and the other end penetrates the left position spool of the reversing valve, and the left position third passage is provided with the left position check valve.

[0012] The beneficial effect of the further scheme is that the left position first passage is conducive to making the hydraulic oil in the starting oil pipe enter the trailer parking brake chamber through the left position first passage when the left position of the reversing valve is communicated with the starting oil pipe, so as to realize the braking or unbraking of the trailer, and the left position check valve is conducive to avoiding the hydraulic oil in the accumulator returning to the left position second passage, so as to affect the braking or unbraking function of the trailer.

[0013] Further, the right-position first passage, the right-position second passage and the right-position third passage are arranged in the right-position spool of the reversing valve, the right-position first passage and the right-position second passage both penetrate the right-position spool of the reversing valve, one end of the right-position third passage communicates with the right-position second passage and the other end penetrates the right-position spool of the reversing valve, the right-position first one-way valve is arranged on the right-position first passage, and the right-position second one-way valve is arranged below the communication point between the right-position second passage and the right-position third passage.

[0014] The beneficial effects of the further scheme are that the right-position first passage is beneficial to make the right position of the reversing valve communicate with the starting oil pipe when the tractor and the trailer are separated (i.e. the starting oil pipe no longer inputs hydraulic oil), the right-position first one-way valve is beneficial to avoid the hydraulic oil left in the trailer parking brake chamber from flowing back to the starting oil pipe, and the right-position second one-way valve is beneficial to avoid the hydraulic oil in the accumulator or the hydraulic oil left in the trailer parking brake chamber from flowing to the brake oil pipe.

[0015] Further, the starting oil pipe communicates with one end of the left-position first passage or one end of the right-position first passage, the brake oil pipe communicates with one end of the left-position second passage or one end of the right-position second passage, the trailer parking brake chamber communicates with the other end of the left-position first passage or the other end of the right-position first passage, the trailer service brake chamber communicates with the other end of the left-position second passage or the other end of the right-position second passage, and the accumulator communicates with the other end of the left-position third passage or the other end of the right-position third passage.

[0016] The beneficial effect of the further scheme is that the starting oil pipe is communicated with one end of the left first passage, the trailer parking brake cavity is communicated with the other end of the left first passage, which represents that the tractor is connected with the trailer, and is conducive to making the hydraulic oil in the starting oil pipe enter the trailer parking brake cavity through the left first passage to realize the release of the trailer brake; the starting oil pipe is communicated with the right first passage, and the trailer parking brake cavity is communicated with the other end of the right first passage, which represents that the tractor is separated from the trailer, and the reversing valve has returned to the original position, that is, the starting oil pipe no longer inputs hydraulic oil; the brake oil pipe is communicated with one end of the left second passage, and the trailer service brake cavity is communicated with the other end of the left second passage, which represents that the tractor is connected with the trailer, and is conducive to making the hydraulic oil in the brake oil pipe enter the trailer service brake cavity through the left second passage to realize the brake of the trailer; the brake oil pipe is communicated with one end of the right second passage, and the trailer service brake cavity is communicated with the other end of the right second passage, which represents that the tractor is separated from the trailer, and the reversing valve has returned to the original position, that is, the brake oil pipe no longer inputs hydraulic oil; the accumulator is communicated with the other end of the left third passage, which represents that the tractor is connected with the trailer, and the hydraulic oil in the brake oil pipe enters the accumulator through the left third passage to charge the accumulator; the accumulator is communicated with the other end of the right third passage, which represents that the tractor is separated from the trailer, and the reversing valve has returned to the original position, that is, the starting oil pipe no longer inputs hydraulic oil, but the hydraulic oil in the accumulator can enter the trailer service brake cavity through the right third passage to realize the brake of the trailer.

[0017] Further, the liquid inlet end and the liquid outlet end of the manual pump are one-to-one communicated with the brake oil pipe and the accumulator, a second one-way valve is arranged between the liquid inlet end of the manual pump and the brake oil pipe, and a third one-way valve is arranged between the liquid outlet end of the manual pump and the accumulator.

[0018] The beneficial effect of the further scheme is that the manual pump is conducive to pumping the hydraulic oil in the trailer service brake cavity into the accumulator when the tractor is separated from the trailer and the reversing valve is manually reversed, so as to reduce the hydraulic pressure in the trailer service brake cavity and release the trailer brake.

[0019] Further, the reversing valve further comprises a manual reversing switch for manually switching the left valve core and the right valve core of the reversing valve.

[0020] The beneficial effect of the further scheme is that the manual reversing switch is conducive to reversing the reversing valve when the tractor is separated from the trailer, so as to realize the release of the trailer brake in cooperation with the manual pump.

[0021] Further, a second pressure switch is further included, which is connected with the accumulator and used for alarming when the pressure of the accumulator is too low.

[0022] The beneficial effect of the further scheme is that the second pressure switch is beneficial to monitor the hydraulic pressure of the accumulator in real time during the normal driving process of the tractor with the trailer, and if the hydraulic pressure in the accumulator is too low, the contact in the second pressure switch is disconnected, reminding the driver to stop and overhaul.

[0023] Further, the first pressure switch and the second pressure switch are electrically connected with the control terminal of the tractor.

[0024] The beneficial effect of the further scheme is that it is beneficial to provide convenience for the driver to understand the hydraulic oil pressure of the starting oil pipe through the first pressure switch, and it is beneficial to provide convenience for the driver to understand the hydraulic oil pressure of the accumulator through the second pressure switch. BRIEF DESCRIPTION OF DRAWINGS

[0025] Figure 1 The hydraulic system schematic diagram provided for the embodiment of the present application;

[0026] Figure 2 The principle diagram of the reversing valve provided for the embodiment of the present application.

[0027] In the drawings, the components represented by each number are listed as follows:

[0028] 1, first pressure switch; 2, electromagnetic valve; 3, reversing valve; 4, hand pump; 5, second pressure switch; 6, starting oil pipe; 7, oil tank; 8, brake oil pipe; 9, accumulator; 10, trailer parking brake cavity; 11, trailer service brake cavity; 12, first check valve; 13, second check valve; 14, third check valve; 301, left first passage; 302, left second passage; 303, left third passage; 304, left check valve; 305, right first passage; 306, right second passage; 307, right third passage; 308, right first check valve; 309, right second check valve; 310, pilot cavity; 311, hand reversing switch. DETAILED DESCRIPTION

[0029] The principles and features of the present application are described below, and the examples are only used to explain the present application, and are not used to limit the scope of the present application.

[0030] As Figure 1 and Figure 2As shown, this embodiment provides an emergency braking system for a tractor-trailer, including: a first pressure switch 1, a solenoid valve 2, a reversing valve 3, and a manual pump 4; the first pressure switch 1, the solenoid valve 2, and the reversing valve 3 are all connected to the starting oil pipe 6; the first pressure switch 1 is electrically connected to the solenoid valve 2 to drive the solenoid valve 2 to reverse; the solenoid valve 2 is connected to the reversing valve 3 to drive the reversing valve 3 to reverse; the solenoid valve 2 is connected to the oil tank 7; the reversing valve 3 is connected to the brake oil pipe 8, the accumulator 9, the trailer parking brake chamber 10, and the trailer service brake chamber 11 to brake or release the trailer brake; the reversing valve 3, the manual pump 4, and the accumulator 9 are sequentially connected in one direction for manually releasing the trailer brake.

[0031] It should be noted that in this embodiment, the reversing valve 3, the manual pump 4, and the accumulator 9 are sequentially connected in one direction. This means that during the manual release of the trailer brake, the hydraulic oil in the trailer travel brake chamber 11 flows sequentially through the reversing valve 3 and the manual pump 4, and finally returns to the accumulator 9, while the pressure in the trailer travel brake chamber 11 decreases, and the trailer brake is released.

[0032] The starting oil pipe 6 is connected to the auxiliary pipeline oil circuit on the tractor to provide hydraulic oil for releasing the trailer's brakes, and the brake oil pipe 8 is connected to the control pipeline oil circuit on the tractor to provide hydraulic oil for braking the trailer.

[0033] When hydraulic oil enters the trailer parking brake chamber 10, the trailer is released from braking; when hydraulic oil enters the trailer service brake chamber 11, the trailer is braked. These principles are existing technologies and will not be elaborated here.

[0034] The beneficial effects of this invention are as follows: the first pressure switch and the solenoid valve facilitate the reversing valve to switch under the hydraulic drive of the starting oil pipe, thereby allowing the hydraulic oil in the starting oil pipe to enter different working valve cores of the reversing valve. Through the connection between the different working valve cores of the reversing valve and the brake oil pipe, accumulator, trailer parking brake chamber and trailer service brake chamber, it is beneficial to enable the trailer to achieve emergency braking function regardless of whether there is a tractor towing it. The manual pump, in conjunction with the reversing valve, accumulator and trailer service brake chamber, is beneficial to achieve quick brake release even when there is no tractor towing.

[0035] Preferred, such as Figure 1 As shown, the solenoid valve 2 is a two-position three-way solenoid valve. The starting oil pipe 6 drives the first pressure switch 1 to switch, which is used to energize the solenoid valve 2 and switch the solenoid valve 2 from the initial lower position to the upper position. A first check valve 12 is provided between the solenoid valve 2 and the brake oil pipe 8.

[0036] It should be noted that in the embodiment, the first one-way valve 12 can prevent the hydraulic oil in the brake oil pipe 8 from entering the upper or lower position of the electromagnetic valve 2.

[0037] The beneficial effect of the above preferred scheme is that the starting oil pipe is in communication with the first pressure switch, which is conducive to the contact of the first pressure switch under hydraulic pressure, so that the electromagnetic valve is powered to reverse, and the hydraulic oil in the starting oil pipe enters the pilot chamber of the reversing valve through the upper position of the electromagnetic valve.

[0038] Preferably, as shown in Figure 1 The reversing valve 3 is a three-position five-way reversing valve, the starting oil pipe 6 is in communication with the pilot chamber 310 of the reversing valve 3 through the upper position of the electromagnetic valve 2, and is used to switch the reversing valve 3 from the right position of the initial state to the left position, the left or right position of the reversing valve 3 is in communication with the starting oil pipe 6, and the pilot chamber 310 is in communication with the oil tank 7 through the lower position of the electromagnetic valve 2.

[0039] The beneficial effect of the above preferred scheme is that the starting oil pipe is in communication with the pilot chamber of the reversing valve through the upper position of the electromagnetic valve, which is conducive to inputting the hydraulic oil in the starting oil pipe into the pilot chamber of the reversing valve, so that the reversing valve is switched from the right position of the initial state to the left position; the left or right position of the reversing valve is in communication with the starting oil pipe, which is conducive to realizing the braking or unbraking of the trailer when the trailer is not pulled by the tractor, in cooperation with the brake oil pipe, the accumulator, the trailer parking brake chamber and the trailer service brake chamber; the pilot chamber is in communication with the oil tank through the lower position of the electromagnetic valve, which is conducive to returning the hydraulic oil in the pilot chamber to the oil tank when the tractor is separated from the trailer (i.e. the starting oil pipe no longer inputs hydraulic oil), so that the reversing valve returns to the initial position.

[0040] Preferably, as shown in Figure 1 and Figure 2 The left position first passage 301, the left position second passage 302 and the left position third passage 303 are arranged in the left position spool of the reversing valve 3, the left position first passage 301 and the left position second passage 302 penetrate the left position spool of the reversing valve 3, one end of the left position third passage 303 is in communication with the left position second passage 302, and the other end penetrates the left position spool of the reversing valve 3, and the left position third passage 303 is provided with a left position one-way valve 304.

[0041] It should be noted that in the embodiment, the left position one-way valve 304 can only make the hydraulic oil flow from one end of the left position third passage 303 in communication with the left position second passage 302 to the other end, but cannot make the hydraulic oil flow from the other end of the left position third passage 303 to the one end in communication with the left position second passage 302.

[0042] The beneficial effect of the above preferred scheme is that the left first passage is conducive to entering the hydraulic oil in the starting oil pipe into the trailer parking brake chamber through the left first passage when the left position of the reversing valve is communicated with the starting oil pipe, so as to realize the brake release of the trailer; and the left one-way valve is conducive to avoiding the backflow of the hydraulic oil in the accumulator to the left second passage, thereby affecting the brake release function of the trailer.

[0043] Preferably, as shown in Figure 1 and Figure 2 The right first passage 305 and the right second passage 306 of the reversing valve 3 are both through the right valve core of the reversing valve 3, one end of the right third passage 307 is communicated with the right second passage 306, and the other end penetrates through the right valve core of the reversing valve 3. The right first one-way valve 308 is arranged on the right first passage 305, and the right second one-way valve 309 is arranged below the communication point of the right second passage 306 and the right third passage 307.

[0044] It should be noted that in the embodiment, the right first one-way valve 308 can only make the hydraulic oil flow from the starting oil pipe 6 to the trailer parking brake chamber 10, and cannot make the hydraulic oil flow from the trailer parking brake chamber 10 to the starting oil pipe 6; and the right second one-way valve 309 can only make the hydraulic oil flow from the brake oil pipe 8 to the trailer parking brake chamber 10, and cannot make the hydraulic oil flow from the trailer parking brake chamber 10 to the brake oil pipe 8.

[0045] The beneficial effect of the above preferred scheme is that the right first passage is conducive to making the right position of the reversing valve communicated with the starting oil pipe when the tractor is separated from the trailer (i.e., the starting oil pipe no longer inputs hydraulic oil); the right first one-way valve is conducive to avoiding the backflow of the hydraulic oil remaining in the trailer parking brake chamber to the starting oil pipe, and the right second one-way valve is conducive to avoiding the hydraulic oil in the accumulator or the hydraulic oil remaining in the trailer parking brake chamber from flowing to the brake oil pipe.

[0046] Preferably, as shown in Figure 1 and Figure 2As shown, the starting oil pipe 6 communicates with one end of the left first passage 301 or one end of the right first passage 305, the brake oil pipe 8 communicates with one end of the left second passage 302 or one end of the right second passage 306, the trailer parking brake cavity 10 communicates with the other end of the left first passage 301 or the other end of the right first passage 305, the trailer service brake cavity 11 communicates with the other end of the left second passage 302 or the other end of the right second passage 306, and the accumulator 9 communicates with the other end of the left third passage 303 or the other end of the right third passage 307.

[0047] The beneficial effects of the above preferred scheme are that the starting oil pipe communicates with one end of the left first passage, the trailer parking brake cavity communicates with the other end of the left first passage, which represents that the tractor is connected with the trailer, and is conducive to making the hydraulic oil in the starting oil pipe pass through the left first passage and enter the trailer parking brake cavity to realize the release of the brake of the trailer; the starting oil pipe communicates with the right first passage, and the trailer parking brake cavity communicates with the other end of the right first passage, which represents that the tractor is separated from the trailer, and the reversing valve has returned to the original position, i.e., the starting oil pipe no longer inputs hydraulic oil; the brake oil pipe communicates with one end of the left second passage, and the trailer service brake cavity communicates with the other end of the left second passage, which represents that the tractor is connected with the trailer, and is conducive to making the hydraulic oil in the brake oil pipe pass through the left second passage and enter the trailer service brake cavity to realize the brake of the trailer; the brake oil pipe communicates with one end of the right second passage, and the trailer service brake cavity communicates with the other end of the right second passage, which represents that the tractor is separated from the trailer, and the reversing valve has returned to the original position, i.e., the brake oil pipe no longer inputs hydraulic oil; the accumulator communicates with the other end of the left third passage, which represents that the tractor is connected with the trailer, and the hydraulic oil in the brake oil pipe enters the accumulator through the left third passage to charge the accumulator; and the accumulator communicates with the other end of the right third passage, which represents that the tractor is separated from the trailer, and the reversing valve has returned to the original position, i.e., the starting oil pipe no longer inputs hydraulic oil, but the hydraulic oil in the accumulator can enter the trailer service brake cavity through the right third passage to realize the brake of the trailer.

[0048] Preferably, as shown in Figure 1 and Figure 2 The liquid inlet end and the liquid outlet end of the manual pump 4 correspondingly communicate with the brake oil pipe 8 and the accumulator 9, the liquid inlet end of the manual pump 4 is provided with the second one-way valve 13 between the brake oil pipe 8, and the liquid outlet end of the manual pump 4 is provided with the third one-way valve 14 between the accumulator 9.

[0049] It should be noted that, in the embodiment, because the brake oil pipe 8 is communicated with one end of the left second passage 302 or one end of the right second passage 306, and the liquid inlet end of the manual pump 4 is communicated with the brake oil pipe 8, the liquid inlet end of the manual pump 4 is communicated with one end of the left second passage 302 or one end of the right second passage 306; because the accumulator 9 is communicated with the other end of the left third passage 303 or the other end of the right third passage 307, and the liquid outlet end of the manual pump 4 is communicated with the accumulator 9, the liquid outlet end of the manual pump 4 is communicated with the other end of the left third passage 303 or the other end of the right third passage 307.

[0050] The second one-way valve 13 and the third one-way valve 14 can only make the hydraulic oil flow from the trailer service brake chamber 11 to the manual pump 4 and then to the accumulator 9 when the reversing valve 3 is switched to the left position, that is, when the tractor and the trailer are separated, the reversing valve 3 is manually switched, the hydraulic oil in the trailer service brake chamber 11 for braking the trailer is flowed to the accumulator 9 to charge the accumulator 9, and finally the hydraulic pressure in the trailer service brake chamber 11 is reduced to release the brake of the trailer.

[0051] The above-mentioned preferred scheme has the beneficial effect that the manual pump is beneficial to pumping the hydraulic oil in the trailer service brake chamber to the accumulator when the tractor and the trailer are separated and the reversing valve is manually switched, thereby reducing the hydraulic pressure in the trailer service brake chamber and releasing the brake of the trailer.

[0052] Preferably, as shown in Figure 2 The reversing valve 3 further comprises a manual reversing switch 311 for manually switching the left valve core and the right valve core of the reversing valve 3.

[0053] The above-mentioned preferred scheme has the beneficial effect that the manual reversing switch is beneficial to switching the reversing valve when the tractor and the trailer are separated, thereby cooperating with the manual pump to release the brake of the trailer.

[0054] Preferably, as shown in Figure 1 The second pressure switch 5 is connected with the accumulator 9 and used for alarming when the pressure of the accumulator 9 is too low.

[0055] The above-mentioned preferred scheme has the beneficial effect that the second pressure switch is beneficial to monitoring the hydraulic pressure of the accumulator in real time during the normal driving of the tractor with the trailer, and if the hydraulic pressure in the accumulator is too low, the contacts in the second pressure switch are disconnected to remind the driver to stop and overhaul.

[0056] Preferably, the first pressure switch 1 and the second pressure switch 5 are electrically connected with the control terminal of the tractor.

[0057] It should be noted that, as shown in Figure 1 The first pressure switch 1 has one terminal electrically connected with the control terminal of the tractor, and the other terminal electrically connected with the electromagnetic valve 2. The electromagnetic valve 2 has a terminal electrically connected with the control terminal of the tractor, so as to realize the signal connection between the first pressure switch 1 and the control terminal of the tractor. The second pressure switch 5 has two terminals both electrically connected with the control terminal of the tractor, so as to realize the signal connection between the second pressure switch 5 and the control terminal of the tractor.

[0058] The above preferred scheme has the advantages of facilitating the driver to know the hydraulic oil pressure of the starting oil pipe through the first pressure switch, and facilitating the driver to know the hydraulic oil pressure of the accumulator through the second pressure switch.

[0059] As shown in Figure 1 and Figure 2 The functions of the present embodiment are described as follows.

[0060] 1. When the tractor is connected with the trailer, the tractor is used to release the brake of the trailer: the tractor controls the starting oil pipe 6 to input hydraulic oil, so as to drive the contact in the first pressure switch 1 to be connected, and the electromagnetic valve 2 is powered to switch the lower position to the upper position in the initial state, so that the hydraulic oil input by the starting oil pipe 6 enters the upper position of the electromagnetic valve 2 (it should be noted that the hydraulic oil input by the starting oil pipe 6 does not flow out from the lower position of the electromagnetic valve 2 in the initial state), and then flows out from the upper position of the electromagnetic valve 2 to the pilot chamber 310 of the reversing valve 3, so as to drive the reversing valve 3 to switch the right position to the left position in the initial state. At this time, the hydraulic oil input by the starting oil pipe 6 enters the left position first passage 301 in the left position of the reversing valve 3, and then enters the trailer parking brake chamber 10 along the left position first passage 301. The pressure of the trailer parking brake chamber 10 is increased, so as to release the brake of the trailer.

[0061] 2. When the tractor is connected to the trailer, the tractor brakes the trailer: In this case, the tractor controls the starter hose 6 and brake hose 8 to simultaneously input hydraulic oil. The hydraulic oil input from the starter hose 6 flows as described above, while the hydraulic oil input from the brake hose 8 will not enter the upper position of the solenoid valve 2 due to the obstruction of the first check valve 12. At this time, part of the hydraulic oil passes through the second check valve 13, the manual pump 4 and the third check valve 14 in sequence and enters the accumulator 9 to charge the accumulator 9. The hydraulic oil after passing through the third check valve 14 is blocked by the left check valve 304 in the left position of the reversing valve 3. The hydraulic oil after passing through the third check valve 14 simultaneously drives the contacts in the second pressure switch 5 to connect and input an electrical signal to the tractor's control terminal. The other part of the hydraulic oil directly enters the left second passage 302 in the left position of the reversing valve 3 and enters the trailer's travel brake chamber 11 along the left second passage 302. The pressure in the trailer's travel brake chamber 11 increases, and the trailer brakes.

[0062] 3. When the tractor is connected to the trailer, during normal operation, the hydraulic oil pressure in the starting oil pipe 6 drops, thus braking the trailer. In this case, the hydraulic oil pressure in the starting oil pipe 6 decreases, the contact in the first pressure switch 1 opens, the solenoid valve 2 returns to its initial lower position, and the hydraulic oil in the pilot chamber 310 flows to the oil tank 7 along the lower position of the solenoid valve 2. The hydraulic pressure in the pilot chamber 310 decreases, and the reversing valve 3 returns to its initial right position under the return force of its own spring.

[0063] It should be noted that: at this time, there is still hydraulic oil in the start-up oil pipe 6. If the pressure of the hydraulic oil is still sufficient to open the right-side first check valve 308 on the right-side first passage 305 of the right-side reversing valve 3, the hydraulic oil will enter the trailer parking brake chamber 10 through the right-side first passage 305, increasing the pressure in the trailer parking brake chamber 10 and releasing the trailer brake. However, at the same time, the hydraulic oil charged in the accumulator 9 will enter the right-side third passage 307 of the right-side reversing valve 3, and then enter the trailer service brake chamber 11 through the right-side third passage 307 and the right-side second passage 306, increasing the pressure in the trailer service brake chamber 11. When the pressure rises, the trailer brakes, which is equivalent to pressing the brake and accelerator pedals simultaneously, and the final result is still braking. If the pressure of the hydraulic oil is insufficient to open the right first check valve 308 on the right first passage 305 in the right position of the reversing valve 3, the hydraulic oil cannot enter the trailer parking brake chamber 10 through the right first passage 305. However, the hydraulic oil charged in the accumulator 9 will enter the right third passage 307 in the right position of the reversing valve 3, and enter the trailer service brake chamber 11 through the right third passage 307 and the right second passage 306. The pressure in the trailer service brake chamber 11 increases, and the trailer brakes.

[0064] 4. When the tractor is connected to the trailer, the hydraulic oil pressure in the accumulator 9 decreases during normal operation, triggering an alarm: When the hydraulic oil pressure in the accumulator 9 decreases, the contacts in the second pressure switch 5 open, triggering an alarm signal. The alarm is sent to the operator through the tractor's control terminal, prompting the driver to stop the vehicle for maintenance.

[0065] 5. When the tractor and trailer are separated, the trailer is braked: In this case, no hydraulic oil is input into the starting oil pipe 6 and the braking oil pipe 8. The solenoid valve 2 returns to the lower position of the initial state. The hydraulic oil in the pilot chamber 310 flows to the oil tank 7 through the lower position of the solenoid valve 2. The hydraulic pressure in the pilot chamber 310 decreases. The reversing valve 3 returns to the right position of the initial state under the rebound force of its own spring. The hydraulic oil in the accumulator 9, after being charged, will not enter the manual pump 4 due to the obstruction of the hydraulic oil by the third check valve 14. The hydraulic oil in the accumulator 9 will flow to the right third passage 307 in the right position of the reversing valve 3, and enter the trailer travel brake chamber 11 through the right third passage 307 and the right second passage 306. The pressure in the trailer travel brake chamber 11 increases, and the trailer is braked.

[0066] 6. When the tractor is reconnected to the trailer after being separated from it, the trailer brake is released by the tractor: In this case, hydraulic oil is re-injected into the tractor control start oil pipe 6. The flow of hydraulic oil is as described in the first case above, which will not be repeated here. Finally, the trailer brake is released.

[0067] 7. When the tractor and trailer are separated, the brakes on the trailer are released: In this case, no hydraulic oil is supplied to the starting oil pipe 6 and the brake oil pipe 8. The solenoid valve 2 returns to its initial lower position. The hydraulic oil in the pilot chamber 310 flows to the oil tank 7 through the lower position of the solenoid valve 2. The hydraulic pressure in the pilot chamber 310 decreases. The reversing valve 3 returns to its initial right position under the return force of its own spring. Therefore, it is necessary to first use the manual reversing switch 311 to manually switch the reversing valve 3 to the left position, and then manually operate the manual pump. 4. Pressurization is performed by continuously pulling the piston of the manual pump 4 to generate suction in the hydraulic chamber of the manual pump 4. This draws the hydraulic oil in the trailer's travel brake chamber 11 through the left-side second passage 302 and the second check valve 13 into the hydraulic chamber of the manual pump 4. Under the thrust generated by the piston movement, the hydraulic oil in the hydraulic chamber of the manual pump 4 is driven through the third check valve 14 and finally reaches the accumulator 9. Finally, the hydraulic oil pressure in the trailer's travel brake chamber 11 decreases, and the trailer is released from braking.

[0068] In the description of the application, it should be understood that the orientation or positional relationship indicated by terms such as "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like is based on the orientation or positional relationship shown in the drawings, and is only for the purpose of facilitating the description of the application and simplifying the description, and does not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation of the application.

[0069] In addition, the terms "first", "second" are only for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined with "first", "second" can explicitly or implicitly include at least one of the features. In the description of the application, the meaning of "a plurality of" is at least two, such as two, three, etc., unless otherwise explicitly specified and limited.

[0070] In the present application, unless otherwise explicitly specified and limited, the terms "mounting", "connection", "connection", "fixing" and the like should be understood broadly, for example, it can be fixedly connected, or it can be detachably connected, or it can be integrated; it can be mechanically connected, or it can be electrically connected; it can be directly connected, or it can be indirectly connected through an intermediate medium; it can be the internal communication of two elements or the interaction relationship between two elements, unless otherwise explicitly limited. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0071] In the present application, unless otherwise explicitly specified and limited, the first feature "on" or "under" the second feature can be that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Moreover, the first feature "above", "over" and "on" the second feature can be that the first feature is directly above or obliquely above the second feature, or it can only mean that the horizontal height of the first feature is higher than that of the second feature. The first feature "below", "under" and "under" the second feature can be that the first feature is directly below or obliquely below the second feature, or it can only mean that the horizontal height of the first feature is less than that of the second feature.

[0072] In the description of the specification, the description of the terms "one embodiment", "some embodiments", "an example", "a specific example", or "some examples" etc. means that the specific features, structures, materials or characteristics described in connection with the embodiment or example are contained in at least one embodiment or example of the present application. In the specification, the illustrative description of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any suitable manner in any one or more embodiments or examples. In addition, the person skilled in the art can combine and combine the different embodiments or examples described in the specification and the features of the different embodiments or examples without contradiction.

[0073] Although the embodiments of the present application have been shown and described above, it is understood that the above-described embodiments are exemplary and are not to be construed as limiting the present application, and those skilled in the art can make changes, modifications, replacements and variations to the above-described embodiments within the scope of the present application.

Claims

1. An emergency braking system for a tractor trailer, comprising: The utility model relates to a kind of trailer brake control system, including: First pressure switch (1), solenoid valve (2), reversing valve (3) and hand pump (4);The first pressure switch (1), the solenoid valve (2) and the reversing valve (3) are communicated with starting oil pipe (6), the first pressure switch (1) is electrically connected with the solenoid valve (2), for driving the solenoid valve (2) reversing, the solenoid valve (2) is communicated with the reversing valve (3), for driving the reversing valve (3) reversing, the solenoid valve (2) is communicated with oil tank (7), the reversing valve (3) is communicated with brake oil pipe (8), energy accumulator (9), trailer parking brake cavity (10) and trailer service brake cavity (11), for trailer brake or release brake, the reversing valve (3), the hand pump (4) and the energy accumulator (9) are sequentially communicated in one direction, for manually releasing trailer brake; Left position first passage (301), left position second passage (302) and left position third passage (303) are equipped in the left position spool of the reversing valve (3), the left position first passage (301) and the left position second passage (302) are all through the left position spool of the reversing valve (3), one end of the left position third passage (303) is communicated with the left position second passage (302), and the other end passes through the left position spool of the reversing valve (3), and left position check valve (304) is equipped on the left position third passage (303); Right position first passage (305), right position second passage (306) and right position third passage (307) are equipped in the right position spool of the reversing valve (3), the right position first passage (305) and the right position second passage (306) are all through the right position spool of the reversing valve (3), one end of the right position third passage (307) is communicated with the right position second passage (306), and the other end passes through the right position spool of the reversing valve (3), and right position first check valve (308) is equipped on the right position first passage (305), and right position second check valve (309) is equipped below the point of communication of the right position second passage (306) with the right position third passage (307); The starting oil pipe (6) is communicated with one end of the left position first passage (301) or one end of the right position first passage (305), the brake oil pipe (8) is communicated with one end of the left position second passage (302) or one end of the right position second passage (306), the trailer parking brake cavity (10) is communicated with the other end of the left position first passage (301) or the other end of the right position first passage (305), the trailer service brake cavity (11) is communicated with the other end of the left position second passage (302) or the other end of the right position second passage (306), and the energy accumulator (9) is communicated with the other end of the left position third passage (303) or the other end of the right position third passage (307).

2. The emergency braking system for a tractor trailer of claim 1, wherein, The electromagnetic valve (2) is a two-position three-way electromagnetic valve, the starting oil pipe (6) drives the first pressure switch (1) to switch, for making the electromagnetic valve (2) power switching, making the electromagnetic valve (2) from the lower position of the initial state to the upper position, the lower position of the electromagnetic valve (2) and the brake oil pipe (8) are provided with a first check valve (12).

3. The emergency braking system for a tractor trailer of claim 1, wherein, The reversing valve (3) is a three-position five-way reversing valve, the starting oil pipe (6) is communicated with the pilot chamber (310) of the reversing valve (3) through the upper position of the electromagnetic valve (2), for making the reversing valve (3) from the right position of the initial state to the left position, the left position or the right position of the reversing valve (3) is communicated with the starting oil pipe (6), the pilot chamber (310) is communicated with the oil tank (7) through the lower position of the electromagnetic valve (2).

4. The emergency braking system for a tractor trailer of claim 1, wherein, The liquid inlet end and the liquid outlet end of the hand pump (4) are communicated with the brake oil pipe (8) and the accumulator (9) one by one, the second check valve (13) is arranged between the liquid inlet end of the hand pump (4) and the brake oil pipe (8), and the third check valve (14) is arranged between the liquid outlet end of the hand pump (4) and the accumulator (9).

5. The emergency braking system for a tractor trailer of claim 1, wherein, The reversing valve (3) further comprises a manual reversing switch (311) for manually switching the left position spool and the right position spool of the reversing valve (3).

6. The emergency braking system for a tractor trailer of claim 1, wherein, Further comprising a second pressure switch (5), the second pressure switch (5) is connected with the accumulator (9), for alarming when the pressure of the accumulator (9) is too low.

7. The emergency braking system for a tractor trailer of claim 6, wherein, The first pressure switch (1) and the second pressure switch (5) are electrically connected with the control terminal of the tractor.

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