Cylinder Head Cover and Cylinder Head Cover Manufacturing Method

Abstract

CYLINDER HEAD COVER AND METHOD FOR MANUFACTURING CYLINDER HEAD COVER. The present invention relates to a cylinder head cover comprising a main body and a laterally projecting portion. The main body is arranged to cover a cylinder head and collect exhaust gas. The laterally projecting portion discharges the exhaust gas into an intake passage. The cylinder head cover includes a cover gas passage through which exhaust gas flows from a main body gas passage to an outlet in the laterally projecting portion. A portion with a minimum passage cross-sectional area of the cover gas passage is provided not in the laterally projecting portion, but in the main body gas passage. The main body has a projecting hole or branch passage at a position in the main body gas passage that is downstream of the portion with a minimum passage cross-sectional area.The main body, the side projection part and the projection branch hole or passage are integrally molded.

Description

Descriptive Report of the Invention Patent for CYLINDER HEAD COVER AND METHOD OF MANUFACTURING CYLINDER HEAD COVER. BACKGROUND

[0001] The present invention relates to a cylinder head cover for an internal combustion engine and to a method of manufacturing a cylinder head cover.

[0002] Exhaust gas is generated within an internal combustion engine, and an exhaust gas recirculation system, which drains the exhaust gas through an intake passage, is configured. Since exhaust gas is a gas containing fuel, it must not be released into the atmosphere from an environmental standpoint. Thus, the exhaust gas is once collected in a cylinder head cover of the internal combustion engine and drains from the cylinder head cover to the intake passage through a pipe, to burn in the internal combustion engine. Due to a negative pressure being generated in the intake passage when the internal combustion engine is operated, the exhaust gas is drawn from the cylinder head cover to the intake passage by the negative pressure.

[0003] An example of a conventional cylinder head cover 170 is shown in Figure 9. When an X-axis, a Y-axis, and a Z-axis are shown in the drawing, the X-axis, the Y-axis, and the Z-axis are orthogonal to each other. A Z-axis direction indicates a vertically upward direction, and both an X-axis direction and a Y-axis direction indicate a horizontal direction. The Y-axis direction indicates a longitudinal direction of the cylinder head cover. The cylinder head cover 170 is a molded component of resin or similar materials, and includes a main body 171, a side projection part 172, a labyrinth passage part 173, a Petition 870190093672, dated 09 / 19 / 2019, page 53 / 85 2 / 27 connecting passage part 174, a branch projection passage 180A and the like. The main body 171 is provided so as to cover a cylinder head of an internal combustion engine, collects the exhaust gas generated in the internal combustion engine, and conducts the collected exhaust gas to the side projection part 172 by means of the labyrinth passage part 173 and the connecting passage part 174. The labyrinth passage part 173 is a passage having a predetermined cross-sectional area, which is formed in a labyrinth shape, through which the exhaust gas flows, and which separates an oil component and the like in the exhaust gas. The connecting passage part 174 has a predetermined cross-sectional area, to connect an outlet part of the labyrinth passage part 173 and an inlet part of the side projection part 172.The side projection part 172 has a cylindrical shape and projects from one side of the main body 171, and a tube 182, to conduct exhaust gas from the cylinder head cover 170 to the intake passage, is connected. The side projection part 172 is made by a forced extraction manufacturing method.

[0004] In a case where a crack, fissure, contraction, or similar occurs in tube 182, connected to the side projection part 172 of the cylinder head cover 170 and to the intake passage, since the exhaust gas leaks into the atmosphere, the crack, fissure, contraction, or similar of tube 182 needs to be detected. A pressure on an upstream side of tube 182 is used to detect the atmosphere, the crack, fissure, contraction, or similar of tube 182. Specifically, the side projection part 172, corresponding to an exhaust gas discharge from the cylinder head cover 170, is equipped with the projection branch passage 180A, which will be connected to a detection tube of one of Petition 870190093672, dated 09 / 19 / 2019, pp. 54 / 85 3 / 27 pressure detector, and the atmosphere, the crack, the fissure, the contraction and the like of tube 182 are detected by determining a pressure in the side projection part 172 by means of the projection branch passage 180A.

[0005] In Japanese patent application publication no. H03172524, a cylinder head cover having a positive crankcase ventilation (PCV) space corresponding to the labyrinth passage portion described above is described. In the cylinder head cover described in Japanese patent application publication no. H03172524, the tube for conducting the exhaust gas discharged from the cylinder head cover to the intake passage is connected to an outlet portion of the PCV space, and a pressure sensor for detecting pressure in the PCV space is connected to the PCV space.

[0006] In Japanese patent application publication No. 2015121195, an exhaust gas recirculation device is described, in which an oil separator, corresponding to the labyrinth passage part described above, is separated from a cylinder head cover. In the cylinder head cover described in Japanese patent application publication No. 2015-121195, the oil separator is fixed to an external part of the cylinder head cover, the cylinder head cover and the oil separator are connected by an upstream tube, and the oil separator and the intake passage are connected by a downstream tube. A branch tube, for connection to a pressure detector, is provided in a separator outlet tube, which is a connecting part to the downstream tube in the oil separator.

[0007] When manufacturing the conventional cylinder head cover, shown in Figure 9, typically, as shown in Figures 10 and 11, the main body 171 is formed by a lower mold. Petition 870190093672, dated 09 / 19 / 2019, pages 55 / 85 4 / 27 JL (metallic mold or similar) and an upper mold JU (metallic mold or similar), and the side projection part 172 is formed by a side mold JS (metallic mold or similar). In this case, a side mold withdrawal direction DX, which is a withdrawal direction of the side mold JS, is a projection direction of the cylindrical side projection part 172, and, in the case of Figures 10 and 11, the side mold withdrawal direction DX is substantially parallel to the X direction. A main body mold withdrawal direction DZ, which is a withdrawal direction of both the lower mold JL and the upper mold JU, is a vertical direction, and, in the case of Figures 10 and 11, the main body mold withdrawal direction DZ is substantially parallel to the Z-axis direction.The cylinder head cover 170, integrally molded by the lower mold JL, the upper mold JU, and the side mold JS, is not provided with the projection branch passage 180A and the labyrinth passage 173 shown in Figure 9. Since the labyrinth passage 173 has a complicated shape, like a labyrinth, the labyrinth passage 173 is mounted separately from the cylinder head cover 170 and attached to the integrally molded cylinder head cover 170 (Figure 2). Furthermore, since a projection direction of the projection branch passage 180A is not parallel to the side mold withdrawal direction DX, shown in Figures 10 and 11, the side projection 172 and the projection branch passage 180A are not integrally molded by the side mold JS. Thus, the side projection section 172 and the projection branch passage 180A are separated.For this reason, the side projection part 172, which does not have the projection branch passage 180A, is formed by the side mold JS, and after the main body 171 and the side projection part 172 are formed as an integral molded component, the projection branch passage 180A is added. Petition 870190093672, dated 09 / 19 / 2019, pp. 56 / 85 5 / 27 is welded or bolted to the side projection part 172 (Figure 12).

[0008] To accurately detect pressure in tube 182, for the purpose of detecting cracks, fissures, shrinkage and the like in tube 182 (refer to Figure 9), it was considered that pressure in the side projection part 172 needs to be detected. Therefore, it was considered that the projection branch passage 180A needs to be provided in the side projection part 172. Unfortunately, as described above, when the side projection part 172 is formed using the JS side mold (refer to Figures 10 and 11), the side projection part 172 and the projection branch passage 180A are not molded integrally. Therefore, the 180A projection branch passage needs to be separately welded, screwed, or similarly fitted, resulting in a larger number of parts and a more complex manufacturing process.The projection branch passage 180A has a simple shape, and it is desirable to reduce the number of parts and the manufacturing process by integral molding of the projection branch passage 180A with the side projection part 172 or the main body 171.

[0009] In addition, a pressure sensor for detecting pressure in the PCV space is provided in the cylinder head cover described in Japanese patent application publication no. H03172524. However, there is no description of a pressure detector for detecting cracks, fissures, shrinkage, and the like in the tube connecting the cylinder head cover to the intake passage. Therefore, a pressure detector for detecting cracks, fissures, shrinkage, and the like in the tube is not provided.

[0010] Furthermore, in the cylinder head cover described in Japanese patent application publication no. 2015121195, although cracks, fissures, shrinkage, and the like in the downstream tube are detected by the pressure detector connected to the outlet tube of the Petition 870190093672, dated 09 / 19 / 2019, page 57 / 85 6 / 27 separator in the oil separator, the crack, fissure, contraction and similar of the upstream tube are not detected. Furthermore, since the oil separator is provided separately, the tube that connects the cylinder head cover with the intake passage is divided into an upstream tube and a downstream tube, so the number of parts is increased.

[0011] The present invention was generated with this point in mind, and in a cylinder head cover in an exhaust gas recirculation system, is directed to provide a cylinder head cover and a method of manufacturing the cylinder head cover, which adequately detects a crack, a fissure, a contraction and the like of an exhaust gas recirculation tube, which connects the cylinder head cover to an intake passage, and which further reduces the number of parts and the manufacturing process. SUMMARY

[0012] According to one aspect of the present invention, a cylinder head cover is provided in an exhaust gas recirculation system, which drains exhaust gas generated in an internal combustion engine from the internal combustion engine to an intake passage. The cylinder head cover includes a main body and a side projection part. The main body is a molded resin or metal component, provided to cover a cylinder head of the internal combustion engine and which collects the exhaust gas. The side projection part is provided to project from one side of the main body and discharges the exhaust gas into the intake passage. The side projection part and the intake passage are connected to each other with a tube. The main body includes a gas passage from the main body, which conducts the exhaust gas. Petition 870190093672, dated 09 / 19 / 2019, pp. 58 / 85 7 / 27 collected gas for the side projection portion. The main body gas passage is a predetermined passage cross-sectional area. The cylinder head cover includes a cover gas passage, through which exhaust gas flows from the main body gas passage to an outlet in the side projection portion. The cover gas passage has a minimum passage cross-sectional area portion, in which the passage cross-sectional area of ​​the cover gas passage is minimal. The minimum passage cross-sectional area portion is not provided in the side projection portion, but in the main body gas passage.The main body has a hole for attaching a pressure detector, which detects pressure in the gas passage of the main body, from an external part of the main body, or from a projecting branch passage, to connect the pressure detector from outside the main body at a downstream position of the minimum cross-sectional area passage. The main body, the lateral projection part, and the hole or projection branch passage are integrally molded.

[0013] According to another aspect of the present invention, a method is provided for manufacturing a cylinder head cover in an exhaust gas recirculation system, which drains exhaust gas, generated in an internal combustion engine, from the internal combustion engine to an intake passage. The method includes providing a main body, which is a molded resin or metal component, that covers a cylinder head of the internal combustion engine and collects the exhaust gas; providing a side projection part, which projects from one side of the main body and discharges the exhaust gas into the intake passage; establishing a gas passage from the main body, which conducts the collected exhaust gas to the part of Petition 870190093672, dated 09 / 19 / 2019, page 59 / 85 8 / 27 lateral projection on the main body, the gas passage of the main body having a predetermined passage cross-sectional area; provide a gas passage from the cover, through which exhaust gas flows from the gas passage of the main body to an outlet of the lateral projection part, the gas passage of the cover having a minimum passage cross-sectional area part, in which a passage cross-sectional area of ​​the gas passage of the cover is the smallest; establish the minimum passage cross-sectional area part not in the lateral projection part, but in the gas passage of the main body; establish a hole to attach a pressure detector, which detects pressure in the gas passage of the main body, from an external side of the main body or from a lateral projection part, to connect the pressure detector from the outside of the main body at a downstream position of the minimum passage cross-sectional area part in the main body;To form the main body with a first mold and a second mold, at least one of which is movable along a mold withdrawal direction of the main body; to form the side projection part with a side mold, which is movable along a side mold withdrawal direction, which is an axial direction of the side projection part and is a direction different from the mold withdrawal direction of the main body; and to form the projection branch hole or passage with one of the first mold and the second mold, or the side mold, to integrally mold the main body, the projection branch hole or passage, and the side projection part. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 is a view to describe an example of a schematic configuration of the entire system of an internal combustion engine.

[0015] Figure 2 is a perspective view to describe a Petition 870190093672, dated 09 / 19 / 2019, pp. 60 / 85 9 / 27 Example of an external appearance of a cylinder head cover.

[0016] Figure 3 is a plan view of the cylinder head cover.

[0017] Figure 4 is a side view of the cylinder head cover.

[0018] Figure 5 is a side view of the cylinder head cover, in which a projection branch passage, in Figure 4, is replaced by a hole.

[0019] Figure 6 is a sectional view taken along line VI - VI in Figure 4.

[0020] Figure 7 is a perspective view to depict the withdrawal directions and similar of a first mold, a second mold, and a side mold, when the cylinder head cover is molded integrally.

[0021] Figure 8 is a plan view of Figure 7.

[0022] Figure 9 is a perspective view to describe an example of an external appearance of a cylinder head cover of the prior art.

[0023] Figure 10 is a perspective view to depict the withdrawal directions and similar of a first mold, a second mold and a side mold, when the cylinder head cover of the prior art is molded integrally.

[0024] Figure 11 is a plan view of Figure 10.

[0025] Figure 12 is a view to describe an example in which a projection branch passage and a labyrinth passage portion are attached to the integrally molded prior art cylinder head cover (the cylinder head cover in which the projection branch passage and the labyrinth passage portion are separated from each other). Petition 870190093672, dated 09 / 19 / 2019, pp. 61 / 85 10 / 27 DETAILED DESCRIPTION OF THE IMPLEMENTATION

[0026] Example of a schematic configuration of the entire system of an internal combustion engine 10 (Figure 1)

[0027] An exemplary embodiment of the present invention will be described below with reference to the drawings. First, an example of a schematic configuration of an entire internal combustion engine system 10 will be described using Figure 1. The present exemplary embodiment will be described using an internal combustion engine 10 (for example, a diesel engine) mounted in a vehicle, as an example of the internal combustion engine.

[0028] The entire system will be described below in order from an intake side towards an exhaust side. On an intake side of an intake pipe 11A, an air filter (not shown) and an intake flow detector 21 (e.g., an intake flow sensor) are provided. The intake flow detector 21 transmits a detection signal, corresponding to an air flow rate drawn in by the internal combustion engine 10, to a controller 50. The intake flow detector 21 is fitted with an intake temperature detector 28A (e.g., an intake temperature sensor). The intake temperature detector 28A transmits a detection signal, corresponding to an intake air temperature passing through the intake flow detector 21, to the controller 50.

[0029] One discharge side of intake tube 11A is connected to one inflow side of a compressor 35, and one discharge side of compressor 35 is connected to one inflow side of intake tube 11B. A turbocharger 30 includes compressor 35, having a compressor impeller 35A, and a turbine 36, having a turbine impeller 36A. The compressor impeller 35A is rotatably driven by the turbine impeller 36A, which is rotatably driven by a Petition 870190093672, dated 09 / 19 / 2019, pp. 62 / 85 11 / 27 exhaust gas, and supercharges the intake air flowing from intake pipe 11A by pumping it into intake pipe 11B.

[0030] In intake pipe 11A on an upstream side of compressor 35, an upstream compressor pressure detector 24A is provided. The upstream compressor pressure detector 24A is, for example, a pressure sensor, and transmits a detection signal, corresponding to a pressure in intake pipe 11A, which is upstream of compressor 35, to the controller 50. In intake pipe 11B (an intake pipe 11B position between compressor 35 and an intermediate radiator 16), downstream of compressor 35, an downstream compressor pressure detector 24B is provided. The downstream compressor pressure detector 24B is, for example, a pressure sensor, and transmits a detection signal, corresponding to a pressure in intake pipe 11B, which is downstream of compressor 35, to the controller 50.

[0031] In the intake pipe 11B, the intermediate radiator 16 is arranged upstream, and a throttle device 47 is arranged downstream of the intermediate radiator 16. The intermediate radiator 16 is arranged downstream of the compressor downstream of the pressure detector 24B, and lowers the temperature of the intake air supercharged by the compressor 35. Between the intermediate radiator 16 and the throttle device 47, an intake temperature detector 28B (e.g., an intake temperature sensor) is provided. The intake temperature detector 28B transmits a detection signal, corresponding to the intake air temperature that was lowered by the intermediate radiator 16, to the controller 50.

[0032] The throttle device 47 actuates a butterfly valve, which adjusts the degree of opening of the intake tube 11B based on a control signal from the controller 50, so that an intake flow rate is adjusted. The controller 50 transmits a signal Petition 870190093672, dated 09 / 19 / 2019, pp. 63 / 85 12 / 27 control to the throttle device 47 based on a detection signal from a throttle opening degree detector 47S (e.g., throttle opening degree sensor) and a desired throttle opening degree, so that a throttle valve opening degree, provided in the intake pipe 11B, is adjusted. The controller 50 obtains the desired throttle opening degree based on the degree of lowering of an accelerator pedal, detected based on a detection signal from an accelerator pedal lowering degree detector 25 and an operating state of the internal combustion engine 10.

[0033] The accelerator pedal drop angle detector 25 is, for example, an accelerator pedal drop angle sensor and is provided on the accelerator pedal. The degree of drop of the accelerator pedal by a driver is detected by the controller 50 based on the detection signal from the accelerator pedal drop angle detector 25.

[0034] A pressure detector 24C is provided downstream of the choke device 47 in the intake pipe 11B, to which a discharge side of a discharge gas recirculation (DGR) pipe 13 is connected. One discharge side of the intake pipe 11B is connected to an inflow side of an intake bypass 11C, and one discharge side of the intake bypass 11C is connected to an inflow side of the internal combustion engine 10. The pressure detector 24C is, for example, a pressure sensor, and transmits a detection signal, corresponding to an intake air pressure, shortly before it flows into the intake bypass 11C, to the controller 50. An EGR gas, flowing from an inflow side of the EGR pipe 13 (connection part with a discharge pipe 12B), is discharged into the intake pipe 11B from the discharge side of the EGR pipe 13 (connection part with the intake pipe 11B). A passage Petition 870190093672, dated 09 / 19 / 2019, pp. 64 / 85 13 / 27 passage, through which the EGR gas flows and which is formed with the EGR pipe 13, corresponds to an EGR passage.

[0035] The internal combustion engine 10 has several cylinders 45A to 45D, and injectors 43A to 43D are provided in the respective cylinders. Fuel is supplied to injectors 43A to 43D by means of a common rail 41 and fuel lines 42A to 42D. Injectors 43A to 43D are driven by a control signal from the controller 50 and inject fuel into the respective cylinders 45A to 45D.

[0036] An exhaust gas recirculation system, for draining the exhaust gas generated in the internal combustion engine 10 to an intake passage (intake pipe 11A), includes a cylinder head cover 70 and a pipe 82. The cylinder head cover 70 is attached to a cylinder head of the internal combustion engine 10 so as to cover the cylinder head (refer to Figure 2), the cylinder head cover 70 is provided with a side projection 72 (refer to Figure 2) for discharging the exhaust gas. The side projection 72 of the cylinder head cover 70 and the intake pipe 11A (corresponding to the intake passage) are connected by the pipe 82 for exhaust gas recirculation.The exhaust gas, generated in the internal combustion engine 10, is collected in the cylinder head cover 70 and is conducted to the intake pipe 11A (corresponding to the intake passage) through the side projection 72 and the pipe 82. Since the intake pipe 11A is located upstream of the compressor 35, a negative pressure is generated during the operation of the internal combustion engine 10. The exhaust gas in the pipe 82 is drawn in by the negative pressure, and the drawn-in exhaust gas burns in the internal combustion engine 10. A pressure detector 81, to detect a crack, fissure, contraction, and the like in the pipe 82, is connected to or attached to the cylinder head cover. Petition 870190093672, dated 09 / 19 / 2019, pages 65 / 85 14 / 27 cylinder head 70. The pressure detector 81 is, for example, a pressure sensor, and transmits a detection signal, corresponding to a pressure in the tube 82, to the controller 50.

[0037] The internal combustion engine 10 is equipped with a rotation detector 22, a coolant temperature device 28C and similar devices. The rotation detector 22 is, for example, a rotation sensor, and transmits a detection signal, corresponding to the number of revolutions of a crankshaft of the internal combustion engine 10 (i.e., the engine speed) to the controller 50. The coolant temperature detector 28C is, for example, a temperature sensor, which detects the temperature of a coolant, for cooling the coolant circulating in the internal combustion engine 10, and transmits a detection signal corresponding to the detected temperature to the controller 50.

[0038] An inflow side of a discharge shunt 12A is connected to a discharge side of the internal combustion engine 10, and an inflow side of the discharge pipe 12B is connected to a discharge side of the discharge shunt 12A. A discharge side of the discharge pipe 12B is connected to an inflow side of the turbine 36, and a discharge side of the turbine 36 is connected to an inflow side of a discharge pipe 12C.

[0039] The inflow side of the EGR pipe 13 is connected to the discharge pipe 12B. The EGR pipe 13 provides communication between the discharge pipe 12B and the intake pipe 11B and recirculates a portion of the exhaust gas in the discharge pipe 12B (corresponding to the discharge passage) to the discharge pipe 11B (corresponding to the intake passage). An EGR cooler 15 and an EGR valve 14 are provided in the EGR pipe 13.

[0040] The EGR valve 14 is provided downstream of the EGR radiator 15 on the EGR pipe 13. The EGR valve 14 adjusts a va Petition 870190093672, dated 09 / 19 / 2019, pp. 66 / 85 15 / 27 EGR gas flow rate, flowing in EGR pipe 13, by adjusting the opening degree of EGR pipe 13 based on a control signal from controller 50.

[0041] The EGR 15 radiator is provided in the EGR 13 pipe. The EGR 15 radiator is a so-called heat exchanger, which is supplied with coolant for cooling, and cools and discharges the EGR gas flowing into it.

[0042] A discharge temperature detector 29 is provided in the discharge tube 12B. The discharge temperature detector 29 is, for example, a discharge temperature sensor, and transmits a detection signal, corresponding to the discharge temperature, to the controller 50.

[0043] One discharge side of the discharge tube 12B is connected to one inflow side of the turbine 36, and one discharge side of the turbine 36 is connected to one inflow side of a discharge tube 12C. The turbine 36 is equipped with variable nozzles 33, which control the flow velocity of the discharge gas to be conducted to the turbine impeller 36A, and the degree of opening of all variable nozzles 33 is adjusted by a nozzle drive 31. The controller 50 transmits a control signal to the nozzle drive 31 based on a detection signal from a nozzle opening detector 32 (e.g., a nozzle opening sensor) and a desired degree of nozzle opening, so that the degree of opening of all variable nozzles 33 is adjusted.

[0044] In the discharge pipe 12B, which is located upstream of turbine 36, a pressure detector upstream of turbine 26A is provided. The pressure detector upstream of turbine 26A is, for example, a pressure sensor, and transmits a detection signal, corresponding to a pressure in the discharge pipe 12B, which is located upstream of turbine 36, to the controller 50. In the discharge pipe Petition 870190093672, dated 09 / 19 / 2019, pp. 67 / 85 16 / 27 12C, which is downstream of turbine 36, a pressure detector downstream of turbine 26B is provided. The pressure detector downstream of turbine 26B is, for example, a pressure sensor, and transmits a detection signal, corresponding to a pressure in the discharge pipe 12C, which is downstream of turbine 36, to the controller 50.

[0045] An exhaust gas purification device 61 is connected to one side of the exhaust pipe 12C. For example, when the internal combustion engine 10 is a diesel engine, the exhaust gas purification device 61 includes an oxidation catalyst, a particulate matter collection filter, a selective reduction catalyst and the like.

[0046] The controller 50 includes at least one control unit 51 (central processing unit - CPU) and a storage device 53. The controller 50 (control unit 51) detects the operational state of the internal combustion engine 10 based on detection signals from various detectors including the detectors mentioned above, not limited to the detectors and actuators shown in Figure 1, and controls the various actuators, including the injectors 43A to 43D, the EGR valve 14, the nozzle actuator 31 and the throttle device 47 mentioned above. The storage device 53 is, for example, a storage device, such as a read-only buffer memory (ROM), and stores programs, data and the like to perform internal combustion engine control, self-diagnosis and the like.

[0047] An atmospheric pressure detector 23 is, for example, an atmospheric pressure sensor, and is provided in the controller 50. The atmospheric pressure detector 23 transmits to the controller 50 a detection signal, corresponding to an atmospheric pressure around the controller 50.

[0048] A vehicle speed detector 27 is, for example, Petition 870190093672, dated 09 / 19 / 2019, pp. 68 / 85 17 / 27 is a vehicle speed detection sensor, and is provided on a wheel or similar part of the vehicle. The vehicle speed detector 27 transmits a detection signal, corresponding to the rotational speed of the vehicle wheel, to the controller 50.

[0049] External appearance and structure of cylinder head cover 70 (Figures 2 to 6)

[0050] An external appearance, structure and similars of the cylinder head cover 70 will be described below with reference to Figures 2 to 6. As shown in Figure 2, the cylinder head cover 70 has a main body 71 and a side projection part 72, and the main body 71 and the side projection part 72 are molded components formed of resin or metal. In Figures 2 to 6, a reference number 180A, shown by a dashed line, shows a position of the projection branch passage in the cylinder head cover of the prior art for easy comparison, and does not show a position of a projection branch passage 80A according to the present exemplary embodiment.

[0051] As shown in Figure 2, the main body 71 is provided to cover the cylinder head of the internal combustion engine 10. The exhaust gas, generated in the internal combustion engine 10, is collected in the main body 71. As shown in Figure 4, the main body 71 has a labyrinth passage part 73, which has a predetermined passage cross-sectional area and is formed so that the exhaust gas flows like a labyrinth, and a connecting passage part 74, which has a predetermined passage cross-sectional area and connects to an outlet of the labyrinth passage part 73 and the side projection part 72. The labyrinth passage part 73 and the connecting passage part 74 form a gas passage of the main body 74, and the gas passage of the main body 75 and the projection part Petition 870190093672, dated 09 / 19 / 2019, pp. 69 / 85 18 / 27 side section 72 forms the gas passage of the cover. The gas passage of the main body 75 is accommodated in the main body 71 and conducts the exhaust gas, collected in the main body 71, to the side projection part 72. The connecting passage part 74 is provided with a minimum passage cross-sectional area 70A, wherein the passage cross-sectional area is the smallest in the gas passage of the cover. Since the labyrinth passage part 73 is labyrinth-shaped, an oily component and similar substances are separated from the exhaust gas that has passed through it.

[0052] As shown in Figures 2 and 3, the side projection part 72 is designed to project from one side of the main body 71 and has a tubular shape. The side projection part 72 discharges the exhaust gas, collected in the main body 71, towards the intake passage (intake pipe 11A) through the pipe 82, as shown in Figure 1. The side projection part 72 and the intake passage (intake pipe 11A) are connected to the pipe 82 for exhaust gas recirculation (refer to Figure 1). The side projection part 72 is manufactured using the forced extraction method.

[0053] As described above, to detect the crack, fissure, contraction and similar of tube 82, shown in Figure 2, by pressure, it was considered that it is necessary to detect the pressure in the lateral projection part 72, used as an inlet part of tube 82. However, through various experiments and simulations, it was found that the crack, fissure, contraction and similar of tube 82 are detected when the pressure is detected downstream of a position where the cross-sectional area of ​​the passage is the smallest in the flow passage, through which the exhaust gas flows from an inner side of the main body 71 to an outlet of the lateral projection part 72. Petition 870190093672, dated 09 / 19 / 2019, pp. 70 / 85 19 / 27

[0054] In the cylinder head cover of the prior art, a part, indicated by reference number 170A shown in Figure 6, is the minimum through-sectional area part. The part, indicated by reference number 170A, is an inlet part of the side projection part 72, and the inlet part became the minimum through-sectional area part in the passage in the side projection part 72, due to a draw-out angle relationship during molding. Thus, a hole, for attaching a pressure detector or a projection branch passage for connection to a pressure detector detection tube, has to be provided downstream of the part indicated by reference number 170A (i.e., in the side projection part 72). In the cylinder head cover of the prior art, there is no part in which the cross-sectional area is smaller than the part indicated by reference number 170A, in the passage in the main body.

[0055] Therefore, in the cylinder head cover 70, described in the present exemplary embodiment, as shown in Figures 3 to 5, the minimum passage cross-sectional area part 70A, in which the passage cross-sectional area is the minimum, is not provided in the side projection part 72, but in the gas passage of the main body 75 in the gas passage of the cover, through which the exhaust gas from the gas passage of the main body 75 flows (the labyrinth passage part 73 and the connection passage part 74) to the outlet of the side projection part 72. Then, a hole 80B (refer to Figure 5) or the projection branch passage 80A (refer to Figure 4), communicating with the gas passage of the main body 75, is provided at a position of the gas passage of the main body 75, which is downstream of the minimum passage cross-sectional area part 70A in the body main 71.

[0056] Furthermore, as shown in Figures 3 and 4, the position Petition 870190093672, dated 09 / 19 / 2019, pp. 71 / 85 20 / 27 of the minimum cross-sectional area of ​​passage 70A and the position of the projecting branch passage 80A (or hole 80B) are particularly established in the connection passage 74 in the main body gas passage 75 (the labyrinth passage 73 and the connection passage 74). Since the connection passage 74 is closer to the tube 82 than the labyrinth passage 73, the connection passage 74 has a high responsiveness to pressure variations in the tube 82.

[0057] As shown in Figure 5, when hole 80B is provided, the pressure detector 81 (refer to Figure 1) is inserted and clamped into hole 80B of an outer part of the main body 71. In a case where hole 80B is formed in the main body 71, when the cylinder head cover 70 is attached to the internal combustion engine, hole 80B is formed to be disposed on a side opposite the cylinder head and to be opened to the side opposite the cylinder head. Thus, as described later, once a main body mold withdrawal direction DZ (refer to Figure 7), at an integral molding moment, and a hole 80B opening direction are made to coincide with each other, the main body 71 and the tubular form 80B are easily molded integrally.

[0058] As shown in Figure 4, when the projection branch passage 80A is provided, the pressure detector sensing tube 81 is connected to the projection branch passage 80A from outside the main body 71. In a case where the projection branch passage 80A is formed in the main body 71, when the cylinder head cover 70 is attached to the internal combustion engine, the projection branch passage 80A is formed on the opposite side of the cylinder head to project to the opposite side. Petition 870190093672, dated 09 / 19 / 2019, pp. 72 / 85 21 / 27 for the cylinder head. Thus, as described later, once the main body mold withdrawal direction DZ (refer to Figure 7), at the time of integral molding, and a projection direction of the projection branch passage 80A are made to coincide with each other, the main body 71 and the projection branch passage 80A are easily molded integrally.

[0059] When the cylinder head cover is attached to the internal combustion engine, a cylinder head cover height, in the direction from one side of the cylinder head to the opposite side of the cylinder head (Z-axis direction in the example of Figures 4 and 5), is referred to as a cylinder head cover height. In this case, the minimum cross-sectional area passage 70A is provided in a part of the cylinder head cover, in which the cylinder head cover height is less than the height of the surrounding cylinder head cover. When the projecting branch passage 80A is provided on a downstream side, in the vicinity of the minimum cross-sectional area passage 70A, the cylinder head cover height is prevented from increasing more than necessary.When hole 80B is provided on the downstream side, in the vicinity of the minimum cross-sectional area passage 70A, the height of the cylinder head cover, including the height of the projection of the pressure detector attached to hole 80B, is prevented from increasing more than necessary. Therefore, the mounting capacity of the cylinder head cover on the vehicle is further improved (space saving). In the description of the present exemplary embodiment, an example in which not hole 80B, but the projection branch passage 80A is provided, will be described later.

[0060] Cylinder head cover manufacturing method 70 Petition 870190093672, dated 09 / 19 / 2019, pp. 73 / 85 22 / 27 (Figures 7 and 8)

[0061] A method of manufacturing the cylinder head cover 70 will be described below with reference to Figures 7 and 8. The main body 71 of the cylinder head cover 70, the projection branch passage 80A (or hole 80B) and the side projection part 72 are molded resin or metal components and are integrally molded.

[0062] As shown in Figures 7 and 8, the main body 71 and the projection branch passage 80A are formed with at least one of a first KU mold (metal mold or similar) and a second KL mold (metal mold or similar), at least one of which is movable along the main body mold withdrawal direction DZ (refer to Figure 7, in this case, Z-axis direction). The projection branch passage 80A (or hole 80B) is formed with the first KU mold or second KL mold and is formed so that the projection direction (or opening direction) is along the main body mold withdrawal direction DZ. For example, in a case where the main body mold withdrawal direction DZ is set in an upward direction and the first KU mold is positioned above the second KL mold, the projection branch passage 80A (or hole 80B) is formed with the first KU mold.Thus, the main body 71 and the projection branch passage 80A (or the hole 80B) are easily molded integrally, and the main body 71 and the projection branch passage 80A (or the hole 80B) are molded simultaneously with the first mold KU and the second mold KL, which are the molds for manufacturing the main body 71. Therefore, the number of parts and the manufacturing process are reduced.

[0063] As shown in Figures 7 and 8, the side projection part 72 is formed by the forced extraction manufacturing method with the Petition 870190093672, dated 09 / 19 / 2019, pp. 74 / 85 23 / 27 side mold KS (metal mold or similar) movable along a side mold withdrawal direction DX (refer to Figures 7 and 8, in this case, the X-axis direction), which is an axial direction of the cylindrical side projection part 72, and which is different from the main body mold withdrawal direction DZ. The side projection part 72 is integrally formed with the main body 71. Thus, the main body 71 and the projection branch passage 80A (or the hole 80B) and the side projection part 72 are integrally molded. Consequently, there is no need for welding or similar (or hole making in the case of the hole) of the projection branch passage 80A (or the hole 80B) in a subsequent process, after the main body 71 and the side projection part 72 are integrally molded, so that the number of parts and the manufacturing process are reduced.

[0064] The cylinder head cover 70 and the method of manufacturing the cylinder head cover 70, according to the present invention, are not limited to the configuration, structure, method of manufacturing and the like, described in the present exemplary embodiment, and various changes, additions and deletions are made without departing from the spirit and scope of the present invention. For example, the turbocharger 30 may be omitted.

[0065] The cylinder head cover and the method of manufacturing the cylinder head cover, according to the present invention, are not limited to the diesel engine, and are applied to various internal combustion engines, such as a gasoline engine.

[0066] In the description of the present exemplary embodiment, although the example, in which the hole 80B is opened on the opposite side to the cylinder head, has been described (refer to Figure 5), the direction of opening of the hole 80B may remain the same direction as that in which the lateral projection part 72 extends. Similarly, in Petition 870190093672, dated 09 / 19 / 2019, pages 75 / 85 24 / 27 description of the present exemplary embodiment, although the example, in which the projection branch passage 80A is arranged on the opposite side to that of the cylinder head, has been described (refer to Figure 4), the projection direction of the projection branch passage 80A may remain the same direction in which the lateral projection part 72 extends.

[0067] In the description of the present exemplary embodiment, although the example in which the minimum cross-sectional area passage part 70A and the projection branch passage 80A (or the hole 80B) are provided in the connection passage part 74 has been described (refer to Figures 4 and 5), the minimum cross-sectional area passage part 70A and the projection branch passage 80A (or the hole 80B) may be provided in the labyrinth passage part 73.

[0068] In the description of the present exemplary embodiment, although the example, in which the minimum through-sectional area portion is provided in the cylinder head cover portion where the height of the cylinder head cover is less than the height of the surrounding cylinder head cover, has been described (refer to Figures 4 and 5), the minimum through-sectional area portion may be provided in a cylinder head cover portion whose height is equal to or greater than the height of the surrounding cylinder head cover.

[0069] In the description of the present exemplary embodiment, although the example, in which the direction of withdrawal of the main body mold DZ is established in the upward direction and the first mold KU is arranged above the second mold KL, has been described, the direction of withdrawal of the main body mold DZ may be established in a substantially horizontal direction and the first mold KU may be arranged on the side of the second mold KL. Petition 870190093672, dated 09 / 19 / 2019, pp. 76 / 85 25 / 27 ADVANTAGEOUS EFFECTS OF THE INVENTION

[0070] One end of an exhaust gas recirculation tube, which carries exhaust gas in a cylinder head cover to an intake passage, is connected to a side projection part of the cylinder head cover, and the other end is connected to the intake passage. To detect a crack, fissure, contraction, and the like in the tube due to pressure, it was considered necessary to detect the pressure in the side projection part used as an inlet part of the tube. However, through various experiments and simulations, it was found that the crack, fissure, contraction, and the like in the tube are detected when the pressure is detected downstream of a position where the cross-sectional area of ​​the passage is the smallest, in an exhaust gas flow passage, from an inner side of a main body of the cylinder head cover to an outlet of the side projection part.

[0071] In a first aspect of the invention, a minimum cross-sectional area passage is provided not in the side projection, but in a gas passage of the main body. Thus, a hole, for attaching a pressure detector that adequately detects a crack, fissure, contraction, and the like in the exhaust gas recirculation pipe, or a branch projection passage for connecting the pressure detector, is located downstream of the minimum cross-sectional area passage in the main body. The number of parts and the manufacturing process are reduced by simultaneously molding the main body and the branch projection passage (or hole) with a mold to form the main body, or by simultaneously molding the side projection and the branch projection passage (or hole) with a mold to form the side projection. Petition 870190093672, dated 09 / 19 / 2019, pp. 77 / 85 26 / 27

[0072] In a second aspect of the invention, by establishing an arrangement position and a direction of opening of the hole to a suitable position and in a suitable direction, respectively, or by establishing an arrangement position and a direction of projection of the projection branch passage to a suitable position and in a suitable direction, respectively, the main body and the hole or projection branch passage are in configurations that are more easily molded integrally.

[0073] In a third aspect of the invention, the minimum cross-sectional area passage and the projection hole or branch passage are placed closer to the exhaust gas recirculation tube in an exhaust gas passage (in a passage in the cylinder head cover), excluding the side projection part. In this way, the pressure to detect the crack, fissure, contraction and the like of the exhaust gas recirculation tube is detected more precisely and more responsively.

[0074] According to a fourth aspect of the invention, when the projection branch passage is provided on a downstream side, in the vicinity of the minimum passage cross-sectional area, the height of the cylinder head cover is prevented from increasing more than necessary. Furthermore, when the hole is provided on the downstream side, in the vicinity of the minimum passage cross-sectional area, the height of the cylinder head cover, including the projection height of the pressure detector, which is attached to the hole, is prevented from increasing more than necessary. Therefore, the mounting capability of the cylinder head cover on the vehicle is further improved (space saving).

[0075] In a fifth aspect of the invention, the minimum cross-sectional area of ​​the passage portion is provided not in the portion of Petition 870190093672, dated 09 / 19 / 2019, pp. 78 / 85 27 / 27 lateral projection, but in the gas passage of the main body. Thus, a hole, to attach a pressure detector, which adequately detects the crack, fissure, contraction and the like of the exhaust gas recirculation pipe or a projection branch passage, to connect the pressure detector, is provided in the gas passage of the main body, which is downstream of the minimum passage cross-sectional area part in the main body. Then, the main body, the hole or projection branch passage, and the lateral projection part are adequately molded integrally by a first mold, a second mold and a lateral mold. Therefore, the number of parts and the manufacturing process are reduced.

[0076] According to a seventh aspect of the invention, the main body and the projection hole or branch passage are suitably and easily molded integrally.

Claims

1. Cylinder head cover (70) in an exhaust gas recirculation system, which drains exhaust gas generated in an internal combustion engine (10) from the internal combustion engine (10) to an intake passage (11A, 11B), the cylinder head cover (70) characterized in that it comprises: a main body (71), which is a molded resin or metal component, which is provided so as to cover a cylinder head of the internal combustion engine (10) and which collects the exhaust gas; and a side projection part (72), which is provided so as to project from one side of the main body (71) and which discharges the exhaust gas into the intake passage (11A, 11B), wherein: the side projection part (72) and the intake passage (11A, 11B) are connected to each other with a tube (82);the main body (71) includes a main body gas passage (75), which conducts the collected exhaust gas to the side projection part (72), the main body gas passage (75) having a predetermined passage cross-sectional area; the cylinder head cover (70) includes a cover gas passage (75, 72), through which the exhaust gas flows from the main body gas passage (75) to an outlet of the side projection part (72), the cover gas passage (75, 72) having a minimum passage cross-sectional area part (70A), in which the passage cross-sectional area of ​​the cover gas passage (75, 72) is the smallest, the minimum passage cross-sectional area part (70A) not being provided in the side projection part (72), but in the main body gas passage (75);Petition 870190093672, dated 09 / 19 / 2019, page 80 / 85 2 / 5 the main body (71) has a hole (80B) for attaching a pressure detector (81), which detects pressure in the gas passage of the main body (75), from an external part of the main body (71), or from a projection branch passage (80A), to connect the pressure detector (81) from outside the main body (71) at a downstream position of the minimum passage cross-sectional area part (70A); and the main body (71), the lateral projection part (72) and the hole (80B) or the projection branch passage (80A) are integrally molded.; 2. Cylinder head cover (70), according to claim 1, characterized in that: in a case wherein the main body (71) has the hole (80B), when the cylinder head cover (70) is attached to the internal combustion engine (10), the hole (80B) is formed on a side opposite the cylinder head and is open to the side opposite the cylinder head; and in a case wherein the main body (71) has the projecting branch passage (80A), when the cylinder head cover (70) is attached to the internal combustion engine (10), the projecting branch passage (80A) is formed on the side opposite the cylinder head to project to the side opposite the cylinder head.

3. Cylinder head cover (70), according to claim 1 or 2, characterized in that: the gas passage of the main body (75) includes a labyrinth passage part (73), which is formed as a labyrinth, and a connecting passage part (74), which connects an outlet of the labyrinth passage part (73) and the side projection part (72); and Petition 870190093672, dated 09 / 19 / 2019, page 81 / 85 3 / 5 the minimum passage cross-sectional area part (70A) and the hole (80B) or the projection branch passage (80A) are provided in the connecting passage part (74).

4. Cylinder head cover (70), according to any one of claims 1 to 3, characterized in that: in one case, a height of the cylinder head cover (70), in a direction from one side of the cylinder head to a side opposite the cylinder head, is referred to as a height of the cylinder head cover, when the cylinder head cover (70) is attached to the internal combustion engine (10); and the minimum passage cross-sectional area part (70A) is provided in a part of the cylinder head cover (70), where the height of the cylinder head cover is less than a height of the surrounding cylinder head cover.

5. Method for manufacturing a cylinder head cover (70) in an exhaust gas recirculation system, which drains exhaust gas, generated in an internal combustion engine (10), from the internal combustion engine (10) to an intake passage (11A, 11B), the method characterized in that it comprises: providing a main body (71), which is a molded resin or metal component, which covers a cylinder head of the internal combustion engine (10), and which collects the exhaust gas; providing a side projection part (72), which projects from one side of the main body (71) and which discharges the exhaust gas into the intake passage (11A, 11B);establish a gas passage from the main body (75), which conducts the collected exhaust gas to the side projection part (72) in the main body (71), the gas passage of the main body (75) having a predetermined passage cross-sectional area; provide a gas passage from the cover (75, 72), through which the exhaust gas flows from the gas passage of the main body (75) to an outlet of the side projection part (72), the gas passage of the cover (75, 72) having a minimum passage cross-sectional area part (70A), in which a passage cross-sectional area of ​​the gas passage of the cover (75, 72) is the smallest; establish the minimum passage cross-sectional area (70A) not in the side projection (72), but in the gas passage of the main body (75);establish a hole (80B) to attach a pressure detector (81), which detects pressure in the gas passage of the main body (75), from an external side of the main body (71) or from a side projection part (80A), to connect the pressure detector (81) from the outside of the main body (71) at a downstream position of the minimum passage cross-sectional area part (70A) in the main body (71); form the main body (71) with a first mold (KU) and a second mold (KL), at least one of which is movable along a mold withdrawal direction of the main body (KS); form the side projection part (72) with a side mold (KS), which is movable along a side mold withdrawal direction (DX), which is an axial direction of the side projection part (72) and is a direction different from the mold withdrawal direction of the main body (DZ);and form the hole (80B) or the projection branch passage (80A) with one of the first mold (KU) and the second mold (KL), or the side mold (KS), to integrally mold the main body (71), the hole (80B) or the projection branch passage (80A) and the Petition 870190093672, dated 09 / 19 / 2019, page 83 / 85 5 / 5 side projection part (72).; 6. Method of manufacturing the cylinder head cover (70), according to claim 5, characterized in that it comprises: forming the hole (80B) or the projection branch passage (80A) with one of the first mold (KU) and the second mold (KL).

7. Method of manufacturing the cylinder head cover (70), according to claim 5 or 6, characterized in that it comprises: establishing the main body mold withdrawal direction (DZ) in an upward direction; arranging the first mold (KU) above the second mold (KL); and forming the hole (80B) or the projection branch passage (80A) with the first mold (KU).

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