DE102019115347A1 - Flow control valve for exhaust gas recirculation - Google Patents

Abstract

The flow control valve 60 to the EGR includes a housing 61, a flow channel 51 for exhaust gas reflux, which is arranged in the housing, and a valve body 63 which is mounted in the flow channel and is rotated or moved by a shaft 62 to open and close the flow channel conclude. When the valve body comes into contact with the flow channel and is in a closed valve state, the valve body is further provided with a coating layer 65 of an elastic body arranged in a contact part of the valve body and / or the flow channel. The coating layer has a rubber layer 66, a binder layer 67 of a fluororesin molded on the rubber layer, and a surface layer 68 of a fluororesin molded on the binder layer.

Description

Territory

The present invention relates to a flow control valve for EGR (exhaust gas recirculation).

background

Patent Document 1 discloses a valve device used in a vehicle. In this valve device, a rubber seal member is used on an outer peripheral portion of a valve so that the rubber seal member is in close contact with the flow channel when the valve is closed.

State of the art

Patent document 1: JP 2018-506816 A

short version

An EGR valve (EGR: exhaust gas recirculation) is used in a high temperature environment and, when the machine is stopped, is completely closed and exposed to condensed water, into which water vapor in the exhaust gas aggregates. For example, since exhaust gas contains nitrogen oxides (NOx) when nitrogen oxides are dissolved in the aggregated water, the aggregated water becomes acidic. When the valve device described in Patent Document 1 is used as a flow control valve for EGR, there is a possibility that deterioration may occur in a rubber seal member due to the aggregated water. Furthermore, since the exhaust gas has a high temperature, there is a fear that the rubber sealing element sticks to the flow channel and thereby causes a malfunction of the valve opening or damage to the rubber sealing element when the valve opens. However, methods to improve these problems have not been fully examined.

short version

According to one aspect of the present invention, a flow control valve ( 60 ) intended. The flow control valve includes a housing ( 61 ), a flow channel ( 51 ) for an exhaust gas return flow, which is arranged in the housing, and a valve body ( 63 ), which is installed in the flow channel and a shaft ( 62 ) is rotated or moved to open and close the flow channel. Furthermore, when the valve body comes into contact with the flow channel and is in a closed valve state, the valve body is covered with a coating layer ( 65 ) an elastic body arranged in a contact part of the valve body and / or the flow channel. The coating layer has a rubber layer ( 66 ), a layer of binder ( 67 ) a fluororesin molded on the rubber layer and a surface layer ( 68 ) a fluororesin formed on the binder layer. Accordingly, the rubber layer is not deteriorated even when the aggregated water is generated, and it does not stick to other elements even when the temperature becomes high. In other words, it is possible to improve the resistance to aggregated water and the resistance to high temperatures.

Figure list

• 1 Fig. 11 is an explanatory diagram showing a schematic configuration of a machine system;
• 2nd 11 is an explanatory diagram showing an intake flow passage of an EGR flow control valve of a first embodiment in cross section;
• 3rd Fig. 11 is an explanatory diagram showing a configuration of a valve seat;
• 4th Fig. 11 is an explanatory diagram showing a cross-sectional configuration of a coating layer;
• 5 Fig. 11 is an explanatory diagram showing an evaluation result with respect to a composition of the coating layer;
• 6 11 is an explanatory diagram showing a schematic configuration of a flow control valve for EGR of a second embodiment;
• 7 Fig. 11 is an explanatory view showing an overcoat layer configuration of the second embodiment in an enlarged manner;
• 8th 11 is an explanatory diagram showing a schematic configuration of a flow control valve for EGR of a third embodiment;
• 9 Fig. 11 is an explanatory view showing an overcoat layer configuration of the third embodiment in an enlarged manner;
• 10th 12 is an explanatory diagram showing a schematic configuration of a flow control valve for EGR of a fourth embodiment;
• 11 Fig. 11 is an explanatory diagram showing an overcoat layer configuration of the fourth embodiment in an enlarged manner;
• 12th 11 is an explanatory diagram showing a schematic configuration of a flow control valve for EGR of a fifth embodiment;
• 13 Fig. 11 is an explanatory view showing an overcoat layer configuration of the fifth embodiment in an enlarged manner;
• 14 11 is an explanatory diagram showing a schematic configuration of a flow control valve for EGR of a sixth embodiment;
• 15 FIG. 12 is an explanatory diagram showing an overcoat layer configuration of the sixth embodiment in an enlarged manner.

Detailed description

First embodiment

As in 1 shown includes a machine system 10th a control unit 15 , a machine 20th , which is an internal combustion engine with a loader 45 acts, an admission system 30th , an exhaust system 40 , and a reflux system 50 .

The machine 20th includes a cylinder 21 , a piston 22 , a cylinder head 23 , a combustion chamber 24th , a spark plug 25th , an intake valve 26 , and an exhaust valve 27 . The combustion chamber 24th is a room surrounded by the cylinder 21 , the piston 22 and the cylinder head 23 . The air required for combustion is the combustion chamber 24th via the inlet valve 26 fed. The fuel can go to the combustion chamber 24th via the inlet valve 26 or can be fed directly to the combustion chamber via an injector (not shown). The spark plug 25th ignites that of the combustion chamber 24th supplied fuel. The exhaust gas generated after combustion is through the exhaust valve 27 drained.

The intake system 30th includes an inlet duct 31 , an air purifier 32 , a compressor 47 a loader 45 , an inlet pipe 33 , an intercooler 34 , a choke 35 and an intake manifold 36 . The inlet duct 31 is a channel that is the air purifier 32 with the machine 20th connects. The air purifier 32 removes dust and dirt when air is let in from the atmosphere. The compressor 47 compresses the air using the pressure of the exhaust gas and sends it to the inlet pipe 33 . The intercooler 34 cools the air, the temperature of which has risen due to the compression. The throttle 35 regulates the amount of air that the machine 20th is fed. The intake manifold 36 distributes the air to a plurality of cylinders of the machine 20th .

The exhaust system 40 includes an exhaust duct 41 , an exhaust manifold 42 , an exhaust pipe 43 , an exhaust gas purification unit 44 , and a turbine 46 of the loader 45 . The exhaust duct 41 is a channel of exhaust gas that the machine 20th connects with the atmosphere. The exhaust manifold 42 sends the exhaust gas discharged from the plurality of cylinders collectively to the turbine 46 . The turbine 46 is with the compressor 47 through a wave 48 connected, is rotated by the pressure of the exhaust gas, and drives the compressor 47 over the wave 48 on. The exhaust pipe 43 is with the downstream side of the turbine 46 connected and the exhaust gas purification unit 44 is on the exhaust pipe 43 arranged. The emission control unit 44 cleans the exhaust gas. The exhaust gas contains the nitrogen oxides NOx, HC, and CO, and the exhaust gas purification unit 44 cleans them. In the event that the machine 20th is a natural intake machine, the loader can 45 be omitted.

The reflux system 50 is a system that returns part of the exhaust gas to the intake system and includes a backflow channel 51 and a flow control valve 60 to the EGR (hereinafter also referred to as “flow control valve 60 " designated). EGR is an abbreviation for exhaust gas recirculation. The backflow channel 51 is a channel for the exhaust gas recirculation, which is the downstream side of the exhaust gas purification unit 44 with the flow control valve 60 connects, and includes a reflux pipe 52 . The return pipe 52 is with an EGR cooler 53 equipped to reduce the temperature of the exhaust gas to be recirculated. The flow control valve 60 is a three way valve between the air purifier 32 of the intake system 30th and the compressor 47 is appropriate.

This in 2nd shown flow control valve 60 includes a housing 61 , a rotating shaft 62 , a valve body 63 , and a valve seat 64 . The valve body 63 is a rotary valve body, which is made by rotating the rotary shaft 62 around the rotating shaft 62 turns around. If the valve body 63 not on the valve seat 64 is the flow of the exhaust gas from the return flow channel 51 to the inlet duct 31 in the housing 61 activated. If the valve body 63 on the valve seat 64 is the flow of the exhaust gas from the return flow channel 51 to the inlet duct 31 in the housing 61 switched off.

3rd shows the design of the valve seat. As in 3rd shown is the valve seat 64 at an end portion of the backflow channel 51 and the shape of the end portion is shaped so that the end portion would be able to conform to the valve body 63 adjust when the valve body 63 closed is. The valve seat 64 includes one Coating layer 65 at an end portion, which is a contact part, the valve body 63 touched.

As in 4th shown includes the overcoat layer 65 a rubber layer 66 , a layer of binder 67 of a fluororesin, and a surface layer 68 of a fluororesin, in that order, from the bottom 69 - Side to the contact side with the valve body 63 . The rubber of the rubber layer 66 is selected, for example, from vinylidene fluoride rubber, hydrogenated nitrile rubber, hydrated rubber, and the like. If the binder layer 67 of the fluororesin and the surface layer 68 of the fluororesin, the firing temperature is 300 ° C or higher. In the present embodiment, the heating is carried out locally and for a short time using a laser or an infrared light, and the burning is completed before the lower rubber layer 66 is affected by the heat of 300 ° C or higher. Thus, the coating layer 65 be set on fire without the rubber layer 66 is affected.

In the flow control valve 60 the water vapor contained in the exhaust gas condenses to produce aggregated water. Because the exhaust gas contains nitrogen oxide (NOx) even if an exhaust gas purification unit 44 is present, the nitrogen oxide dissolves in the aggregated water and the aggregated water becomes acidic. As in 5 the resistance of the coating layer is shown 65 against aggregated water when the binder layer improves 67 of the fluororesin and the surface layer 68 of the fluororesin on the rubber layer 66 be shaped. At the same time, even when heated by the high temperature of the exhaust gas, the coating layer sticks 65 not with the valve body 63 and resistance to high temperatures is also improved. If the rubber layer 66 is formed from an acid-resistant rubber or if there is a coating on the rubber layer 66 applied, at least the resistance to aggregated water can be improved.

As described above, the flow control valve includes 60 according to the first embodiment, a coating layer 65 of an elastic body on the section of the return flow channel 51 is arranged, the valve body 63 touched. Because the coating layer 65 the rubber layer 66 , the binder layer 67 of the fluororesin molded on the rubber layer and the surface layer 68 on the binder layer 67 molded fluororesin, even in an environment where the aggregated water is generated and the temperature rises, can deteriorate the rubber layer 66 due to the aggregated water and sticking due to a high temperature can be suppressed. In other words, it is possible to improve the resistance to aggregated water and the resistance to high temperatures.

In the first embodiment, the coating layer is 65 on a section of the backflow channel 51 arranged of the valve body 63 touched. However, a coating layer can be 65 also on a section of the valve body 63 be arranged of the return flow channel 51 touches, for example, on an outer peripheral portion of the valve body 63 . Furthermore, the coating layer 65 both on the section of the return flow channel 51 that the valve body 63 touched, arranged as at the same time on the portion of the valve body 63 which is the backflow channel 51 touched.

In addition, the coating layer 65 only be arranged on the contact part with which the valve body 63 other elements during the opening and closing of the valve body 63 touches, or it can be arranged over the contact part that touches other elements. In the event that the coating layer 65 is only arranged on the contact part, which during the opening and closing process of the valve body 63 Touching other elements, it is possible to change the amount of the coating layer to be formed 65 to reduce and therefore the amount of for the coating layer 65 reduce materials used. For the other case that the coating layer 65 Arranged above the contact part that touches other elements, impairments due to, for example, the aggregated water in an area outside the contact part that touches other elements can be suppressed.

Second embodiment

6 and 7 show a flow control valve 70 according to the second embodiment. The flow control valve 70 is a throttle valve that comes from the rotating shaft 72 is rotated and one in the housing 71 shaped flow channel 75 through the valve body 73 opens and closes. A lip 74 is on a portion of the valve body 73 arranged and touches an inner wall of the flow channel 75 when the valve body 73 closed is. The lip 74 includes a coating layer of an elastic body, and the coating layer includes a rubber layer, a binder layer of a fluororesin molded on the rubber layer, and a surface layer of a fluororesin molded on the binder layer. This makes it possible even in the flow control valve 70 , which is the throttle valve, the deterioration of the rubber layer due to the aggregated water and the bonding due to high temperature in an environment in which the aggregated water is produced and the temperature increased to suppress. In other words, it is possible to improve the resistance to aggregated water and the resistance to high temperatures.

Third embodiment

8th and 9 show a flow control valve 80 according to the third embodiment. The flow control valve 80 is a throttle valve that comes from the rotating shaft 82 is rotated and one in the housing 81 shaped flow channel 84 through the valve body 83 opens and closes. A groove 85 is in the flow channel 84 shaped and an elastic sealing element 86 gets into the groove 85 built-in. By arranging the sealing element 86 in the groove 85 it is possible to move the sealing element 86 due to the opening and closing of the valve body 83 to suppress. The sealing element 86 may not be in the groove 85 arranged. A coating layer 87 is on the inside of the flow channel 84 of the sealing element 86 shaped. If the valve body 83 is closed, touches an outer edge of the valve body 83 the coating layer 87 . The coating layer 87 includes a rubber layer, a binder layer of a fluororesin molded on the rubber layer, and a surface layer of a fluororesin molded on the binder layer. This makes it possible even in the flow control valve 80 that has a valve body 83 which is the throttle valve, suppresses deterioration of the rubber layer due to the aggregated water and bonding due to high temperature in an environment where the aggregated water is generated and the temperature increases. In other words, it is possible to improve the resistance to aggregated water and the resistance to high temperatures.

Fourth embodiment

10th and 11 show a flow control valve 90 according to the fourth embodiment. The flow control valve 90 is a valve through a valve body 93 by a rotating shaft 92 is rotated, one in a housing 91 shaped flow channel 95 closes or opens. A valve seat 94 is in the flow channel 95 attached and a coating layer 96 an elastic material is on the valve seat 94 arranged. If the valve body 93 is closed, touches an outer edge of the valve body 93 the coating layer 96 . The coating layer 96 contains a rubber layer 97 , a layer of binder 98 one on the rubber layer 97 molded fluororesin and a surface layer 99 one on the binder layer 98 molded fluororesin. This can impair and stick the rubber layer 97 in an environment where the aggregated water is produced and the temperature rises. In other words, it is possible to improve the resistance to aggregated water and the resistance to high temperatures. As can be seen from the second, third and fourth embodiments, the binder layer can be formed on either the valve body or the flow channel. In addition, the binder layer can be formed both on the valve body and at the same time on the flow channel.

Fifth embodiment

12th and 13 show a flow control valve 100 according to the fifth embodiment. The flow control valve 100 has a valve body 103 at an end portion of a shaft 102 on. If the wave 102 in one direction along the wave 102 moves, the valve body is seated 103 on the valve seat 104 or is from the valve seat 104 Cut. This will make one in the case 101 shaped flow channel 106 closed or opened. In the flow control valve 100 12 is a coating layer (not shown) in the vicinity of the valve body described in the first to fourth embodiments 103 arranged. The flow control valve 100 also includes an oil seal 105 on a section where the shaft 102 from the flow channel 106 the housing 101 protrudes facing. The oil seal 105 has a coating layer 107 similar to the coating layer described in the first to fourth embodiments on a portion that the wave 102 touched. The coating layer includes a rubber layer, a binder layer of a fluororesin molded on the rubber layer, and a surface layer of a fluororesin molded on the binder layer. This can impair and stick the rubber layer of the oil seal 105 in an environment where aggregated water is produced and the temperature rises. In other words, it is possible to improve the resistance to aggregated water and the resistance to high temperatures. The coating layer described in the first to fourth embodiments may not be near the valve body 103 arranged.

Sixth embodiment

14 and 15 show a flow control valve 110 according to the sixth embodiment. The flow control valve 110 according to the sixth embodiment has a valve body 113 at an end portion of a shaft 112 on. By turning the shaft 112 around the wave 112 the valve body sits around 113 on a valve seat 114 on or off the valve seat 114 provided separately, and closes or opens the in the housing 111 shaped flow channel. In the flow control valve 100 12 is a coating layer (not shown) in the vicinity of the valve body described in the first to fourth embodiments 113 arranged. The flow control valve 110 also includes an oil seal 115 on a section where the shaft 112 from the flow channel to the housing 111 protrudes facing. The oil seal 115 has a coating layer 116 similar to the coating layer described in the first to fourth embodiments on a portion that the shaft 112 touched. The coating layer includes a rubber layer, a binder layer of a fluororesin molded on the rubber layer, and a surface layer of a fluororesin molded on the binder layer. This can impair and stick the rubber layer of the oil seal 115 in an environment where aggregated water is produced and the temperature rises. In other words, it is possible to improve the resistance to aggregated water and the resistance to high temperatures. As can be seen from the fifth and sixth embodiments, the coating layer can be arranged not only on the valve body and the valve seat that opens and closes the flow passage, but also on the oil seal of the shaft that rotates and moves the valve body. The coating layer includes a rubber layer, a binder layer of a fluororesin molded on the rubber layer, and a surface layer of a fluororesin molded on the binder layer. The coating layer described in the first to fourth embodiments may not be near the valve body 113 arranged.

The present invention can be implemented in the following manner.

According to one aspect of the present invention, a flow control valve ( 60 ) intended. The flow control valve includes a housing ( 61 ), a flow channel ( 51 ) for an exhaust gas return flow which is arranged in the housing, and a valve body ( 63 ), which is installed in the flow channel and a shaft ( 62 ) is rotated or moved to open and close the flow channel. Furthermore, when the valve body comes into contact with the flow channel and is in a closed valve state, the valve body is covered with a coating layer ( 65 ) an elastic body arranged in a contact part of the valve body and / or the flow channel. The coating layer has a rubber layer ( 66 ), a layer of binder ( 67 ) a fluororesin molded on the rubber layer and a surface layer ( 68 ) a fluororesin formed on the binder layer.

(2) In the above aspect, the valve body is a rotating valve body that opens and closes the flow channel by being rotated by a shaft, and an end portion of the flow channel has a shape that can be fitted to the valve body when the valve body is closed and the end portion may include a coating layer. According to this configuration, even in a flow control valve with a rotating valve body, deterioration of the coating layer in an environment where the temperature rises and aggregated water is generated can be suppressed, and the resistance to the aggregated water and the resistance to high temperatures can be improved.

(3) In the above configuration, an oil seal ( 105 ) for sealing the outer periphery of the shaft and a layer similar to the coating layer at a portion contacting the shaft. According to this configuration, deterioration of the oil seal and sticking of the oil seal can be suppressed even in an environment in which the temperature rises and the aggregated water is generated.

(4) According to one aspect of the present invention, there is a flow control valve ( 100 ) in front. The flow control valve includes a housing ( 101 ), a flow channel ( 106 ) for an exhaust gas return flow, which is arranged in the housing, a valve body ( 103 ), which opens and closes the flow channel by a shaft ( 102 ) installed, rotated and moved in the flow channel, and an oil seal ( 105 ) for sealing the outer circumference of the shaft. The oil seal includes a coating layer having a rubber layer, a binder layer of a fluororesin molded on the rubber layer, and a surface layer of a fluororesin molded on the binder layer. According to this configuration, deterioration of the oil seal and sticking of the oil seal can be suppressed even in an environment in which the temperature rises and the aggregated water is generated.

(5) In the above-mentioned embodiment, the rubber layer can be formed from one of the materials vinylidene fluoride rubber, hydrogenated nitrile rubber or hydrogen ring rubber. According to this configuration, it is possible to use a rubber made of one of vinylidene fluoride rubber, hydrogenated nitrile rubber or hydrogen ring rubber as a rubber layer even in an environment in which the temperature rises and the aggregated water is generated.

(6) In the above configuration, the coating layer can only on one contact part be arranged, which touches other elements when opening and closing the valve body. According to this configuration, the amount of the coating layer to be used can be reduced so that the cost can also be reduced.

It is possible to implement the present invention in various ways. For example, the present invention can be implemented by a seal structure in a flow control valve, a protection method of a seal, and the like, in addition to a flow rate control valve.

QUOTES INCLUDE IN THE DESCRIPTION

This list of documents listed by the applicant has been generated automatically and is only included for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Patent literature cited

• JP 2018506816 A [0003]

Claims (6)

Flow control valve for exhaust gas recirculation, comprising: a housing (61); a flow channel (51) for an exhaust gas return flow, which is arranged in the housing; a valve body (63) mounted in the flow channel and rotated or moved by a shaft (62) to open and close the flow channel; and a covering layer (65) of an elastic body which is arranged in a contact part of at least one selected from the valve body or flow channel when the valve body comes into contact with the flow channel in order to achieve a closed state, wherein the coating layer includes a rubber layer (66), a binder layer (67) of a fluororesin molded on the rubber layer, and a surface layer (68) of a fluororesin molded on the binder layer. Flow control valve for exhaust gas recirculation after Claim 1 wherein the valve body is a rotary valve body that opens and closes the flow channel by being rotated by the shaft, an end portion of the flow channel has a shape capable of conforming to the valve body when the valve body is closed, and Coating layer is arranged at the end portion of the flow channel. Flow control valve for exhaust gas recirculation after Claim 1 or 2nd further comprising: an oil seal (105) formed to seal the outer periphery of the shaft, the oil seal having a layer similar to the coating layer on a part contacting the shaft. Flow control valve for exhaust gas recirculation, comprising: a housing (101); a flow channel (106) for an exhaust gas return flow, which is arranged in the housing; a valve body (103) mounted in the flow channel and rotated or moved by a shaft (102) to open and close the flow channel; an oil seal (105) configured to seal the outer periphery of the shaft, wherein the oil seal includes a rubber layer, a binder layer of a fluororesin molded on the rubber layer, and a surface layer of a fluororesin molded on the binder layer. Flow control valve for exhaust gas recirculation according to one of the Claims 1 to 4th , wherein the rubber layer consists of one of the materials vinylidene fluoride rubber, hydrogenated nitrile rubber, and hydrogen ring rubber. Flow control valve for exhaust gas recirculation according to one of the Claims 1 to 4th , wherein the coating layer is arranged only on a contact part which touches other elements when the valve body is opened or closed.

Images