KR20130066834A - Urea solution sender - Google Patents

Abstract

PURPOSE: A urea solution sender is provided to be applied to a selective catalytic reduction apparatus and to thaw a urea solution. CONSTITUTION: A urea solution sender includes a head (110), a suction pipe (121), a heat generating part (130), a valve device (140), a level sensor (150), and a temperature sensor. The head has a ventilation path connecting the inside and outside of a urea solution storage tank. The suction pipe is extended from the head to the inside of the tank. The heat generating part has a heating wire connected to an external power source. The valve device has a sub-valve body for opening the ventilation path. The level sensor measures the height of the surface level of a urea solution. The temperature sensor measures the temperature of the urea solution.

Description

Urea Water Sender {UREA SOLUTION SENDER}

The present invention relates to a urea water sender installed in a urea water storage tank in a selective catalytic reduction device using urea solution as a reducing agent.

Since diesel engines contain various harmful substances in the exhaust gas discharged after combustion, various types of diesel particulate filter have been developed to reduce various harmful substances and particulate matters emitted after combustion in diesel engines. Diesel particulate filter is a method using a diesel oxidation catalyst (DOC; Diesel Oxidation Catalyst) that converts the components of hydrocarbon and carbon monoxide contained in the exhaust gas into water and carbon dioxide by an oxidation reaction by a catalyst, respectively, Diesel Particulate Filter (DPF), which collects particulate matter and burns it by heat of exhaust gas, and selective catalytic reduction (SCR) to reduce nitrogen oxides contained in exhaust gas to nitrogen and oxygen. Selective Catalytic Reduction) may be used.

In the selective catalytic reduction method, the nitrogen oxide contained in the exhaust gas is reduced to nitrogen and oxygen using a reducing agent such as ammonia. In particular, the use of urea aqueous solution as the reducing agent is called a urea water-selective catalytic reduction device. In the urea water-selective catalytic reduction apparatus, urea as a reducing agent is stored in a storage tank in the form of an aqueous solution (hereinafter referred to as urea solution) and urea solution installed in the storage tank is supplied through a urea water sender.

1 schematically shows an example of a conventional urea water-selective catalytic reduction apparatus. The urea solution stored in the urea water storage tank 20 is sent to the urea injection device 30 through the urea water sender 22, and is injected into the catalyst exhaust device 40 by the urea injection device 30. The urea water-selective catalytic reduction device shown in FIG. 1 is configured to thaw urea solution that is susceptible to freezing in winter or cold weather, and uses heat of the engine 10 as a heat source for thawing. That is, the urea water-selective catalytic reduction device shown in FIG. 1 is configured to circulate the cooling water heated in the engine 10 in the urea water storage tank 20 to thaw the frozen urea solution. To this end, a supply pipe 11 and a recovery pipe 12 for supplying and recovering cooling water are installed between the engine 10 and the urea water storage tank 20, and inside the urea water storage tank 20. The circulation pipe 21 for circulating the cooling water is provided. Cooling water heated in the engine 10 is supplied to the circulation pipe 21 installed in the urea water storage tank 20 through the supply pipe 11 to thaw the frozen urea solution. The cooling water passing through the circulation pipe 21 is recovered toward the engine 10 through the recovery pipe 12 and is heated by the engine 10 again.

However, in the urea-selective catalytic reduction device illustrated in FIG. 1, the coolant of the engine 10 may reach a temperature suitable for thawing the frozen urea solution only after a certain time after the initial start-up of the engine. . Therefore, in the case of a diesel vehicle employing the urea water-selective catalytic reduction device having the above-described structure, there is a problem that the urea water-selective catalytic reduction device does not operate normally at the initial start-up of the diesel engine in the winter or cold season.

KR 10-0792927 B1

The present invention is to solve the above problems, it is an object of the present invention to provide a urea water sender used in the selective catalytic reduction device and configured to thaw the urea solution.

Another object of the present invention is to provide a urea water sender for preventing leakage or backflow of urea solution stored in the urea water storage tank.

A urea water sender is provided for the selective catalytic reduction device and installed in the urea water storage tank for storing the urea solution. The urea water sender according to an embodiment of the present invention includes a head mounted on the urea water storage tank, the head having an air passage communicating with the inside and the outside of the urea water storage tank, and extending from the head to the inside of the urea water storage tank. Independently moving with respect to the main valve body and the main valve body disposed in the head, the heat generating portion having a suction pipe, a heating wire extending from the head to the inside of the urea water storage tank, and connected to an external power source; It is also possible to include a valve device having a secondary valve body capable of opening the air passage in a state where the main valve body closes the air passage.

The valve device includes a main valve chamber communicating with the aeration passage and the interior of the urea water storage tank, and a subvalve chamber communicating with the interior of the main valve chamber and the urea water storage tank, wherein the main valve body is movably housed in the main valve chamber. May be movably housed in the subvalve chamber.

The sub-valve chamber is formed inside the main valve body, the sub-valve chamber has a through hole communicating with the inside of the urea water storage tank, and the sub valve body may open and close the through hole.

The valve body may be supported toward the vent by the first spring, and the secondary valve body may be supported toward the vent by the second spring.

The main valve chamber is formed on the lower surface of the head, the head may be provided with a support plate is formed through the communication with the main valve chamber and coupled to the lower surface of the head.

In addition, the valve device includes a main valve chamber formed on the lower surface of the head and communicating with the aeration passage and the interior of the urea water storage tank, and the main valve body is closed in the first position and the passage for receiving the main passage and opening the aeration passage. And a sub-valve chamber which is movable between the second positions to communicate with the aeration passage, and a sub-valve chamber communicating with the interior of the through-hole and the urea water storage tank. It may be openable.

The main valve body may be supported toward the first position or the second position by a spring in the main valve chamber.

The valve device further includes a cap mounted in the sub valve chamber and having a through hole communicating with the inside of the urea water storage tank, and the sub valve body may be supported toward the through hole of the cap by a spring.

The main valve body has a hexagonal column shape, and the side surface of the main valve body may be concave toward the center of the main valve body.

Some or all of the heat generating portions may have a coil shape.

It may further include a level sensor for measuring the height of the water surface of the urea solution.

The level sensor includes a tubular member extending from the head, a circuit board disposed inside the tubular member, a plurality of reed switches mounted on the circuit board at regular intervals, and movably mounted along the outer surface of the tubular member. It may also include a float having a permanent magnet that acts on the reed switch.

It may further include a temperature sensor for measuring the temperature of the urea solution.

Since the urea water sender according to the present invention includes a heating portion in which a heating wire is embedded, the urea solution frozen in winter can be thawed in a short time. In addition, part or all of the heat generating portion has a coil shape, so that the contact area between the heat generating portion and the urea solution is widened, thereby further shortening the thawing time of the frozen urea solution.

In addition, the urea water sender opens and closes the air passage by a valve device having a main valve body and a sub-valve body, thereby preventing the urea solution stored in the urea water storage tank from flowing backward when the vehicle is driven or rolled over a steep slope. Can be. In addition, when the sub-valve body moves relative to the main valve body while the main valve body shields the air passage, air in the urea water storage tank may leak to the outside when an abnormal air pressure occurs in the urea water storage tank. . Therefore, the air pressure inside the urea water storage tank can be maintained at an appropriate level.

1 is a schematic view showing a conventional urea water-selective catalytic reduction device.
2 is a view showing the urea water sender according to an embodiment of the present invention.
3 is a perspective view of the urea water sender of FIG. 2.
4 is an exploded perspective view of the urea water sender of FIG. 3.
5 is a cross-sectional view taken along line VV of FIG. 3.
6 is an exploded perspective view showing the valve device of FIG.
FIG. 7 is a plan view illustrating a state in which the main valve body of FIG. 6 is accommodated in the main valve chamber. FIG.
FIG. 8 is a partial cross-sectional view of the head of FIG. 3, showing a state where the main valve body rests on the support plate. FIG.
FIG. 9 is a partial sectional view of the head of FIG. 3, showing a state in which the air passage is closed by the main valve body. FIG.
FIG. 10 is a partial cross-sectional view of the head of FIG. 3, showing a state where the air passage is opened by the sub-valve body.

Hereinafter, with reference to the accompanying drawings will be described an embodiment of the urea water sender according to the present invention.

Referring to FIG. 2, the urea water sender 100 of the present invention is used in a selective catalytic reduction device (specifically, urea water-selective catalytic reduction device) and installed in a urea water storage tank 80 for storing a urea solution. do. The urea water storage tank 80 has an upper wall 81 and a bottom wall 82. Urea water storage tank 80 is not limited to the size and shape shown in FIG. The urea water sender 100 is connected to the urea supply device 90 by pipes 111a and 111b (or a hose or the like). Urea water (or urea solution) stored in the urea water storage tank 80 is transferred or recovered to the urea supply device 90 through the urea water sender 100, and the urea supply device 90 converts the urea water into a catalytic converter. Supply to the urea injection device 70 coupled to (60). The urea injection device 70 injects urea water into the catalytic converter 60.

The urea water sender 100 is coupled to the urea water storage tank 80 such that a portion thereof is exposed to the outside of the urea water storage tank 80 and the other portion is placed inside the urea water storage tank 80. The urea water sender 100 has a heating device for thawing the frozen urea water by electric power when the urea water stored in the urea water storage tank 80 is frozen or frozen. In addition, the urea water sender 100 has a valve device for preventing urea water stored in the urea water storage tank 80 from leaking or flowing back out of the urea water storage tank 80. In addition, the urea water sender 100 is configured to communicate the inside and the outside of the urea water storage tank 80 at a high pressure in response to the high pressure inside the urea water storage tank 80 by the valve device.

3 and 4, the urea water sender 100 according to an embodiment includes a head 110, a suction pipe 121, a return pipe 122, a heating unit 130, and a valve device. 140, a level sensor 150, and a temperature sensor 160.

The head 110 functions as a support of the urea water sender 100. The head 110 is detachably mounted to the upper wall 81 of the urea water storage tank 80. Therefore, when the urea water sender 100 does not operate normally, the operator separates the urea water sender 100 from the urea water storage tank 80 to easily check, repair, or replace the urea water sender 100. can do.

The head 110 includes a disc-shaped base 110a, a flange 110b formed on an outer circumferential surface of the base 110a, and a housing 110c formed on an upper side of the base 110a. The flange 110b serves to couple the head 110 to the upper wall 81 of the urea water storage tank 80 by screws or bolts. In addition, a ring-shaped sealing member 110d may be interposed between the flange 110b and the upper wall 81. As another example, threads may be formed in the base and the top wall 81 of the head 110, such that the base of the head 110 may be screwed into the top wall 81. The sealing member 110e and the cover 110f are coupled to the upper side of the housing 110c by screws or bolts. As shown in FIG. 4, the head 110 includes a suction port 111, a return port 112, a ventilation port 113, an electrical connector 114, and a support plate 115. In this embodiment, the main valve chamber 116 constituting the valve device 140 is formed on the lower surface of the head 110.

The suction port 111 and the return ports 111 and 112 are coupled to the housing 110c of the head 110 and connected to the urea supply device 90 by the suction pipe and the recovery pipes 111a and 112a. The vent port 113 is coupled to the housing 110c of the head 110 and functions as an air passage connecting the inside and the outside of the urea water storage tank 80. The electrical connector 114 is coupled to the housing 110c of the head 110. The electrical connector 114 is configured to be connected with a corresponding electrical connector extending from the vehicle power supply and electronic control device. The heat generating unit 130, the level sensor 150, and the temperature sensor 160 operate by receiving power from the power supply device through the electrical connector 114. Detection signals generated by the level sensor 150 and the temperature sensor 160 are also transmitted to the electronic control apparatus of the vehicle through the electrical connector 114. The support plate 115 is coupled to the lower surface of the head 110 by screws or bolts.

The suction pipe 121 is fixed to the lower side of the head 110 is connected to the suction port 111, and extends into the urea water storage tank (80). The suction pipe 121 serves to suck the urea solution stored in the urea water storage tank 80. The urea solution sucked through the suction pipe 121 is supplied to the urea supply device 90 through the suction port 111 and through the pipe 111a. The suction pipe 121 has a filter 121a mounted at a lower end thereof. The filter 121a filters the impurities contained in the urea solution when the urea solution is inhaled.

Return pipe 122 is fixed to the lower side of the head 110 is connected to the return port 112, and extends into the urea water storage tank (80). The return pipe 122 serves to return the remaining urea solution from the urea supply device 90 to the urea injection device 70 to the urea water storage tank 80. That is, the urea solution is returned to the urea water storage tank 80 through the pipe 112a, the return port 112, and the return pipe 122 from the urea supply device 90.

The heating unit 130 serves to thaw the frozen urea solution. The heat generating unit 130 extends from the lower side of the head 110. In order to increase the surface area where the heat generating unit 130 and the urea solution are in contact, part of the coil is wound in a coil shape. The heat generating unit 130 includes a heating wire 131, an insulating member 132, and a thermal conductor 133. The heating wire 131 is electrically connected to the electrical connector 114. When electric power is supplied to the heating wire 131 through the electrical connector 114, the heating wire 131 generates heat. The insulating member 132 is an electrical insulating member disposed to surround the heating wire 131. The insulating member 132 prevents the current flowing along the heating wire 131 from being transmitted to the thermal conductor 133. The thermal conductor 133 transfers heat generated from the heating wire 131 to the urea solution and prevents corrosion of the heating wire 131 and the insulating member 132. The thermal conductor 133 is formed as a coating surrounding the insulating member 132. In one embodiment, the thermal conductor 133 is formed of a magnesium material in consideration of thermal conductivity and weight.

The level sensor 150 is for measuring the height of the water surface of the urea solution stored in the urea water storage tank 80. The level sensor 150 includes a tubular member 151, an insulating member 152, a circuit board 153, a reed switch 154, a float 155, a permanent magnet 156, And a stopper 157.

The tubular member 151 extends from the bottom surface of the head 110. The lower end of the tubular member 151 may be sealed by the sealing cap 151a or closed without the sealing cap. The tubular member 151 is made of a metal material having corrosion resistance, and may have a length corresponding to the distance between the top wall 81 and the bottom wall 82 of the urea water storage tank 80.

An insulating member 152 is inserted into the tubular member 151, and a circuit board 153 is disposed inside the insulating member 152. The plurality of reed switches 154 are mounted on the circuit board 153 at regular intervals.

The reed switch 154 includes a glass tube 154a filled with an inert gas and two contacts 154b and 154c spaced apart from the inside of the glass tube 154a. The contacts 154b and 154c are made of ferromagnetic material, are magnetized, and have elastic restoring force. When the permanent magnet 156 approaches while the current is applied to the contacts 154b and 154c, the magnetic force of the permanent magnet 156 acts on the glass tube 154a, causing a magnetic attraction between the contacts 154b and 154c. Works. As a result, the contacts 154b and 154c come into contact with each other so that the reed switch 154 is in an ON state through which current can flow between the contacts 154b and 154c. When the permanent magnet 156 is far from the reed switch 154, the contacts 154b and 154c are separated from each other by an elastic restoring force, and the reed switch 154 can flow a current between the contacts 154b and 154c. It turns off.

The float 155 floats on the water surface of the stored urea solution, has a cylindrical shape, and is fitted to the tubular member 151. Thus, the float 155 is slidable along the longitudinal direction of the tubular member 151. To this end, the bore 155a through which the tubular member 151 passes is formed in the float 155 to penetrate up and down. In this embodiment, the float 155 has a cylindrical shape, but the float may have a polygonal columnar shape in which the bore penetrates up and down. The permanent magnet 156 is embedded in the float 155. The stopper 157 is coupled to the lower end of the tubular member, and serves to prevent the float 155 from escaping from the lower end of the tubular member 151.

The float 155 floats on the water surface of the urea solution and slides along the tubular member 151 according to the height of the water surface. When the permanent magnet 156 embedded in the float 155 is close to any one of the plurality of reed switches 154, the reed switch is turned on. Based on the position of the reed switch turned on, the height of the surface of the urea solution can be detected to measure the remaining amount of the urea solution.

The temperature sensor 160 may be installed at the lower end of the circuit board 153 to measure the temperature of the urea solution (see FIG. 4). For example, the temperature sensor 160 is installed to correspond to the height of the lower end of the suction pipe 121. Therefore, by measuring the temperature of the urea solution in the vicinity of the suction pipe 121 in real time, it is possible to determine whether the heating unit 130 is operating.

5 and 6, a main valve chamber 116 is formed on the lower surface of the head 110 to accommodate a component for performing a valve function as a component of the valve device 140. The main valve chamber 116 is concave upward from the lower surface of the head 110. The main valve chamber 116 communicates with the vent port 113 by the vent passage 113a. After the valve device 140 is accommodated in the main valve chamber 116, the support plate 115 is coupled to the bottom surface of the head 110. The support plate 115 has a through hole 115a, and the through hole 115a is formed in the support plate 115 so as to lie inside the cross-sectional shape of the main valve chamber 116. The valve device 140 is configured to move up and down in the main valve chamber 116. The valve device 140 closes the aeration passage 113a when the vehicle runs on a steep slope or overturns, and the urea water storage tank 80 when abnormal air pressure occurs in the urea water storage tank 80. It serves to communicate the inside of the world with the outside.

The valve device 140 will be described with reference to FIGS. 6 to 10. The valve device 140 includes a main valve body 141, a sub valve body 142, a first spring 143, a second spring 144, and a cap 145.

The main valve body 141 is movably housed in the main valve chamber 116. The main valve body 141 has a substantially hexagonal columnar shape. As shown in FIG. 7, the surface 141d of each side between the upper and lower surfaces of the main valve body 141 is concave toward the center of the main valve body 141. That is, the main valve body 141 has a hexagonal column shape with concave side surfaces. By such a structure, the clearance gap 116a of substantially elliptical cross section is formed between the side surface of the main valve body 141 and the inner wall surface of the main valve chamber 116. As shown in FIG. Therefore, the air flow path defined by the main valve body 141 and the inner wall of the main valve chamber 116 in the state where the valve device 140 is accommodated in the main valve chamber 116 becomes wider than when the surface of each side is flat. .

The main valve body 141 includes a plug portion 141a, a sub valve chamber 141b, and a vent hole 141c. The plug portion 141a protrudes from the upper surface of the main valve body 141 and has a generally conical shape. The plug part 141a is fitted to the end of the air passage 113a to open and close the air passage 113a. The sub-valve chamber 141b is a portion accommodating the sub-valve body 142 and is selectively communicated with the air passage 113a and the main valve chamber 116 through the vent hole 141c.

The sub-valve body 142 is held in the sub-valve chamber 141b and is movable up and down relative to the main valve body 141. The sub-valve body 142 has a conical plug portion 142a and a cylindrical stem portion 142b extending upward from the plug portion 142a. The plug portion 142a selectively opens and closes the through hole 145a of the cap 145, and the stem portion 142b is guided by the second spring 144.

The lower end of the first spring 143 is placed on the support plate 115, and the upper end is placed inside the main valve body 141. In this embodiment, the first spring 143 consists of a compression coil spring. The first spring 143 elastically supports the main valve body 141 (valve device 140) upwardly (that is, toward the air passage 113a). When the urea water sender 100 is placed in a direction substantially perpendicular to the ground (ie, when the parts extending from the head 110 such as the suction pipe 121 are positioned almost perpendicular to the ground), the first spring ( 143 is compressed by the weight of the valve device 140. When a force greater than the own weight is applied to the valve device 140 in a direction opposite to the direction in which the own weight acts, the first spring 143 helps the valve device 140 to move upward. In this embodiment, the first spring 143 is disposed inside the main valve body 141, but the first spring 143 is outside the main valve body 141, for example, in the main valve chamber 116. It may be disposed between the upper surface of the) and the upper surface of the main valve body (141).

The second spring 144 is disposed around the stem portion 142b of the sub valve body 142. The lower end of the second spring 144 is placed on the upper surface of the plug portion 142a of the secondary valve body 142, and the upper end is placed on the upper surface of the secondary valve chamber 141b of the main valve body 141. In this embodiment, the second spring 144 consists of a compression coil spring. The second spring 144 elastically supports the sub valve body 142 downward. That is, the second spring 144 biases the sub valve body 142 toward the cap 145.

The cap 145 is configured to be detachably coupled to the lower end of the sub valve chamber 141b of the main valve body 141. For example, the lower end of the sub-valve chamber 141b and the inner circumferential surface of the cap 145 may be formed with a screw, and the cap 145 may be screwed to the lower end of the sub-valve chamber 141b. Therefore, maintenance or replacement of the sub valve body 142 and the second spring 144 can be facilitated. The cap 145 prevents the sub valve body 142 from being separated from the sub valve chamber 141b. The cap 145 is in the shape of a hollow truncated cone and has a through hole 145a. The through hole 145a may be opened and closed by the plug portion 142a of the subvalve body 142 as the subvalve body 142 moves relative to the main valve body 141.

8 to 10 show an example of the operation of the valve device.

FIG. 8 shows a state in which the main valve body 141 lies on the support plate 115 as an example of the operation of the valve device 140 (hereinafter, this state is referred to as a first state). This first state appears during normal operation, such as a vehicle traveling on a flat surface. In the first state, the urea water storage tank 80 communicates with the outside and the inside of the urea water storage tank 80 maintains a normal pressure. Also, in the first state, the urea water sender 100 is oriented approximately perpendicular to the ground. Therefore, the valve device 140 in the first state is placed on the support plate 115 while compressing the first spring 143 by its own weight (hereinafter, the position of the valve device 140 in the first state is set to the first position). ). The sub-valve body 142 is elastically supported toward the cap 145 by the second spring 144. In the first state, the internal air of the urea water storage tank 80 is a clearance 116a between the through hole 115a of the support plate 115 and the side surface of the main valve body 141 and the main valve chamber 116 (see FIG. 7). ), Through the air passage 113a, and the third port 113 in order to flow out. In addition, the outside air may pass through the reversely as described above may be introduced into the urea water storage tank (80).

FIG. 9 illustrates a state in which the air passage 113a is closed by the main valve body 141 as another example of the operation of the valve device 140 (hereinafter, such a state is referred to as a second state). This second state appears when the vehicle is positioned or rolled over on a steep ramp, and in the second state, the urea water storage tank 80 is not in communication with the outside. When the vehicle is positioned or rolled over on the steep slope, the urea water sender 100 and the valve device 140 are also inclined or rolled over in accordance with the inclination of the vehicle. In this case, the force acting vertically toward the support plate 115 among the components of the force due to the weight of the valve device 140 is reduced. In addition, when at least a part of the valve device 140 is immersed in the urea solution, buoyancy force acts on the valve device 140. Therefore, the combined force due to the elastic restoring force of the first spring 143 and the buoyancy of the valve device 140 is greater than the force due to the weight of the valve device 140. As a result, the valve device 140 moves away from the support plate 115 toward the air passage 113a, and the plug portion 141a of the main valve body 141 is fitted into the air passage 113a (hereinafter, in a second state). The position of the valve device 140 in the second position). Therefore, even if the vehicle is located on the steep slope or rolled over, it is possible to prevent the urea solution stored in the urea water storage tank 80 from leaking or flowing back out of the urea water storage tank 80. When the vehicle leaves the steep slope or is restored from the overturn state to the normal state, the buoyancy of the valve device 140 is reduced and the force acting vertically toward the support plate 115 among the components of the force caused by the weight of the valve device 140. This increases. Accordingly, the valve device 140 is placed on the support plate 115 while compressing the first spring 143. That is, the valve device 140 returns from the second state to the first state.

FIG. 10 shows a state in which the air passage 113a is opened by the sub-valve body 142 as another example of the operation of the valve device 140 (hereinafter, such a state is referred to as a third state). In this third state, the urea water storage tank 80 communicates with the outside in response to the high pressure generated in the urea water storage tank 80. The interior of the urea water storage tank 80 may be placed under high pressure due to a rapid increase in the internal pressure of the stored urea solution. In this case, the internal air of the urea water storage tank 80 is quickly discharged through the gap 116a by the pressure difference between the inside and the outside of the urea water storage tank 80. In this process, the valve device 140 moves away from the support plate 115 toward the aeration passage 113a by the rapid movement of air to a second state. Thereafter, due to the pressure difference between the inside and the outside of the urea water storage tank 80, the subvalve body 142 moves toward the aeration passage 113a while compressing the second spring 144, thereby causing the subvalve body 142. The plug portion 142a of the cap 145 is separated from the through hole 145a to open the through hole 145a. Therefore, the air under high pressure in the urea water storage tank 80 is provided with the through hole 115a of the support plate 115, the through hole 145a of the cap 145, the sub valve chamber 141b, and the main valve body 141. The through hole 141c, the through passage 113a, and the third port 113 in order to flow out to the outside. As the air inside the urea water storage tank 80 flows outward, the pressure difference between the inside and the outside of the urea water storage tank 80 is reduced. When the internal pressure of the urea water storage tank 80 returns to normal, the valve device 140 moves toward the support plate 115 by its own weight. The sub-valve body 142 moves toward the cap 145 by the elastic restoring force of the second spring 144, and the through hole 145a of the cap 145 is formed by the plug portion 142a of the sub-valve body 142. It is closed. As a result, the valve device 140 returns from the third state to the first state. In the return process of the valve device 140, the main valve body 141 and the sub-valve body 142 can move at the same time, any one of the main valve body 141 and the sub-valve body 142 moves first and the other You can also move later.

In the above-described embodiment, the main valve chamber 116 constituting the valve device 140 is formed on the lower surface of the head 110, and the main valve chamber 141 including the sub valve body 142 is the main valve chamber ( 116). The valve device 140 may be provided in the urea water sender 100 in a different manner. For example, the valve device may be constituted by a single cylindrical part defining a main valve chamber and having a through hole at the bottom thereof, and configured in such a manner that a main valve body having a sub-valve chamber and a sub-valve body therein is movably received. It may be. In this embodiment, the main valve chamber need not be formed on the lower surface of the head 110, and the aforementioned valve device may be coupled to communicate with the aeration passage 113a on the lower surface of the head 110.

It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the spirit or scope of the invention. It will be clear to those who have knowledge of.

70: urea injection device
80: urea water storage tank
90: urea supply device
100: urea water sender
110: head
121: suction pipe
122: return pipe
130: heating unit
140: valve device
150: level sensor
160: temperature sensor

Claims (13)

Urea water sender used for selective catalytic reduction device and installed in urea water storage tank for storing urea solution,
A head mounted to the urea water storage tank, the head having an air passage communicating the inside and the outside of the urea water storage tank;
A suction pipe extending from the head into the urea water storage tank;
A heating unit extending from the head to the inside of the urea water storage tank and having a heating wire connected to an external power source;
A valve device disposed on the head and having a main valve body that opens and closes the air passage and a sub-valve body that is movable independently of the main valve body and opens the air passage in a state in which the main valve body closes the air passage.
Element number sender including. The method of claim 1,
The valve device includes a main valve chamber communicating with the aeration passage and the urea water storage tank, and a subvalve chamber communicating with the main valve chamber and the urea water storage tank,
The main valve body is movably housed in the main valve chamber and the sub valve body is movably housed in the sub valve chamber.
Urea water sender. The method of claim 2,
The secondary valve chamber is formed inside the main valve body,
The sub-valve chamber has a through hole communicating with the inside of the urea water storage tank,
The sub-valve body opens and closes the through hole.
Urea water sender. The method of claim 3,
The main valve body is supported toward the vent by a first spring,
The secondary valve body is supported toward the through hole by a second spring,
Urea water sender. The method of claim 2,
The main valve chamber is formed on the lower surface of the head,
The head is provided with a support plate is formed in the through hole communicating with the main valve chamber and coupled to the lower surface of the head
Urea water sender. The method of claim 1,
The valve device has a main valve chamber formed on the lower surface of the head and communicating with the aeration passage and the interior of the urea water storage tank,
The main valve body is accommodated in the main valve chamber and is movable between a first position for opening the vent and a second position for closing the vent, and communicating with the vent and the passage and the urea water. Has a sub-valve chamber in communication with the interior of the storage tank,
The sub-valve body is accommodated in the sub-valve chamber to open and close the through hole of the main valve body.
Urea water sender. The method according to claim 6,
The main valve body is supported toward the first position or the second position by a spring in the main valve chamber.
Urea water sender. The method according to claim 6,
The valve device further includes a cap mounted to the sub-valve chamber and having a through hole communicating with the inside of the urea water storage tank,
The sub-valve body is supported toward the through hole of the cap by a spring
Urea water sender. The method according to claim 6,
The main valve body has a hexagonal column shape, and the side surface of the main valve body is concave toward the center of the main valve body.
Urea water sender. 10. The method according to any one of claims 1 to 9,
Some or all of the heat generating portions have a coil shape
Urea water sender. The urea water sender according to any one of claims 1 to 9, further comprising a level sensor for measuring the height of the water surface of the urea solution. The method of claim 11, wherein the level sensor,
A tubular member extending from the head,
A circuit board disposed inside the tubular member;
A plurality of reed switches mounted to the circuit board at regular intervals,
A float having a permanent magnet mounted movably along the outer surface of the tubular member and acting inside the reed switch.
Element number sender including. The urea water sender according to any one of claims 1 to 9, further comprising a temperature sensor for measuring the temperature of the urea solution.

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