JPH06508192A - Vehicle exhaust gas temperature control device - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed description of the invention] Vehicle exhaust gas temperature control device The present invention can be used to reduce the temperature of automobile exhaust gases, especially air pollutants. The present invention relates to a device for controlling the temperature of a catalyst or a catalyst muffler.

As is known, a catalytic muffler is a device inserted into the automobile exhaust pipe. It has very small passageways with a very large overall surface area, allowing the gas to enter the environment. porous separation along this wall where the reaction upon completion of gas combustion takes place before being discharged Has walls. The reaction tends to increase the temperature of the muffler and It may cause irreparable damage.

Therefore, it is necessary to continuously monitor the temperature at the muffler, which requires heat exchange to the muffler. This is done by a thermocouple inserted in the relationship, and the thermocouple is connected by a shielded conductor. the control station is connected to a control station located in a low temperature area; The cable is terminated with two or more conductors with connectors at their opposite ends. There is.

When one or more predetermined temperature thresholds are exceeded, The control station performs switching between the conductors (corrected depending on the , it generates a warning signal for the driver and alerts him to conditions that could lead to damage to the muffler. I will inform you.

For example, the connector is connected to the battery and to the warning light on the dash board. , thereby causing the warning light to emit intermittently when the first temperature threshold is reached. It begins to glow and gradually increases the intermittent frequency continuously. provide these features A suitable signal for It will be done. Presumably, if the maximum threshold is exceeded, the car has a chance of catching fire. In response to this, engine operation is prohibited.

Known devices of this type are simple in construction and generally reliable, but also However, there are some drawbacks and limitations.

In fact, from this structural point of view, it is necessary to use a car to install a control station. An opening is provided in the body and the thermocouple is connected to the control station using electrical conductors and connectors. and connect the control station to the power source and user. This applies to manufacturing and The existence of degrading connections is a non-negligible cost in terms of construction and assembly. This leads to insufficient reliability.

Due to disturbances picked up by electrical signals that are even lower from an operational point of view. and problems due to probe cold junction correction errors.

It is an object of the present invention to overcome the limitations and disadvantages of the state of the art and, in particular, to The object of the present invention is to provide a device with reduced costs and improved reliability.

The present invention achieves these objectives by providing a thermocouple and a control station electrically connected to the thermocouple. one end connected to said control station and the other end terminated with a connector. a catalyst comprising at least two conductive wires which are mutually insulated and externally shielded; In a device for controlling the temperature of automobile exhaust gas at a control station is placed in an elongated liquid-tight metal container with two opposed axial passages. and the thermocouple is directly connected to the entrance of the control station through one of the passageways. connected, the conductor is directly connected to the control station and the first part of the sealed container for controlling the temperature of automobile exhaust gas, characterized in that it exits from the passage of 2. Achieved by equipment.

According to the preferred embodiment, direct connection of thermocouples to the control station is unnecessary. This is done by a thermocouple connection cable that is insulated by the machine.

The above-mentioned features and other features are some preferred and limiting features of the control device of the invention. It will become clear from the examples below. Referring to the drawing, FIG. 1 is a side view showing the structure of the device according to the invention.

FIG. 1A is a cross-sectional view taken along line A--A in FIG.

FIG. 2 is a diagram showing another embodiment of this device.

FIG. 3 is an electrical circuit diagram connected to the device of the present device.

Referring to FIG. Lobe 1, specifically an insulated thermal junction type rKJ type chromel alumel thermocouple. include.

The elongated thermocouple has a nose-shaped seal attached to the lower part of the thermocouple. and a fixed cap 11, the upper part of which includes a part 15. 15 is provided for electrical connection to the control station described below. It has a mineral insulated cable that houses a pair of thermocouple conductors.

According to the invention, a control step is provided for controlling the operation of the device and shown schematically by the dashed line. The section 13 is a generally cylindrical metal container made of electroplated steel, for example. It is enclosed within the container 2 and includes a pair of passages 5 and 6 facing each other in the axial direction. This capacity The device has a structure that prevents fluid from leaking, especially liquid, and the thermocouple 1 is It is directly connected to the control station through passage 5. used here, also The expression "directly connected" as used below refers to a permanent connection without an intermediate connecting member. Must be understood as synonyms.

1A is a sheet surrounded by an inorganic insulator 20 filling the cylindrical body 15; The structure of a cable 15 consisting of a pair of conductors 16 and 17 with terminals 18 and 19 is shown below. show.

At opposite ends of the metal container 2, two or more conductors are inserted through an axial passage 6. An extension cable 3 consisting of a wire comes out, and this extension cable 3 has an address at its end. connector for connecting the alarm circuit to the onboard electrical equipment that provides power to the probe circuit. It is equipped with connector 4.

Preferably, said circuit consisting of an SMD integrated device has a temperature indicated by a thermocouple. The switching operation of the cable 3 can be started depending on the temperature level, and the thermocouple can be It supplies a voltage in the mV range. Next, a related example will be explained with reference to FIG. .

A control station is installed to prevent the extension cable 3 from twisting close to the container 2. A coiled cable 10 is arranged coaxially with the cable around the cable 3 at the exit of the cable. It is. In another embodiment shown in FIG. 2, the same parts as shown in FIG. or using similar reference numerals to designate corresponding parts. Thermocouple 1 and control A direct connection to the control station 13 is made using an inorganic insulated thermocouple. A compensating extension of a predetermined length inserted between the connecting cable 15 and the control station 13 This is done via cable 7. The externally shielded cable is made of polymer insulation. The rim is a traditional type of cable. The wires are soldered and the joints The part is enclosed within a resin seal socket or metal transition part 8, and the metal transition part Minute 8 gives rigidity to the joint and protects it. Extension cable 3 has 4 conductors It is connected to a connector 9 equipped with many terminals.

The structure described above provides a high degree of flexibility in locating the control station and The station is enclosed away from hot areas. However, usually The length of the cold cable 7 ranges from 20 cm to 2 meters, and the length of the thermocouple has a length ranging from 10 cm to 1 meter.

FIG. 3 shows the electrical circuit of the device according to the invention, with the same reference numerals as in the previous drawings; are used to indicate the same or equivalent parts.

As can be seen in the drawing, a control station 13 is connected to the thermocouple 1 on one side, On the other side, four insulated conductors A, B, C and D protected by a shield 14 are connected, and four-way connectors are connected to the conductive wires. You can see it in the drawing , conductor A is grounded at the vehicle reference numeral 21, and conductor C is connected to the connected to the positive terminal of the battery (in case of negative ground connection) through switch 22 . Furthermore, the positive terminal of the battery, opposite the light warning, is connected to conductor B.

When the probe temperature is below the first threshold, conductor B is insulated from ground. , the lamp 23 goes out. When the first temperature threshold is exceeded, the probe is intermittently grounded at a frequency proportional to the measured temperature, thereby cutting off the lamp. It glows continuously and its frequency increases with temperature.

For example, the pre-threshold at temperatures above 1000 degrees C, as shown in the m3 diagram. A fourth conductor is provided which is activated when . Of course, those skilled in the art As will become apparent, other structures, configurations, and modes of operation are possible.

The advantages provided by the control device of the invention are clear from what has been described above.

In fact, the device does not require a fixed control station on the vehicle body; component (thermocouple control station connector), and in one embodiment , configured to be disconnected with a similar extension cable, thereby facilitating manufacturing and assembly. This reduces costs.

In addition, this device has a large disturbance rejection capacity and has a thermocouple and control station. In other words, areas where the signal level is weak are integrated. Furthermore, within the known device completely eliminates compensation errors at cold junctions that occur and are not easily predictable. I can leave.

Although this invention has been described with reference to certain preferred embodiments, there is no limitation to what is described herein. and includes other variations and modifications apparent to those skilled in the art.

Submission of translation of written amendment (Article 184-8 of the Patent Law) November 30, 1993 1. Display of patent application PCT/IT 92100062 2. Name of the invention Vehicle exhaust gas temperature control device 3. Patent applicant Address: Castelvetro, Piacentino, Cuurcere, Ron, Italy Go, 28 5. Date of submission of written amendment June 3, 1993 6. List of attached documents (1) One translation of the written amendment Due to disturbances picked up by electrical signals that are even lower from an operational point of view. and probe cold junction compensation errors.

Such an arrangement is known, for example, from European Patent Application No. 0236659. Among them, thermocouples placed in catalytic silencers are particularly It is electrically connected to a control circuit connected to an optical signal device on the board.

Japanese Patent Application Publication No. 88919/1988 discloses a hardware for connecting a sensor and a modulator. The harness is reciprocatingly connected via a protective connection. It is formed by two insulated wires of different lengths.

Japanese Patent Application Publication No. 63506 of 1972 discloses a thermocouple inserted into an exhaust system. A temperature sensing device consisting of coaxial conductors welded together at the outer part of the thermocouple Regarding the location.

DE 24 06 073 A1 controls the temperature of a catalytic silencer Regarding the electrical configuration, the connection between the thermocouple and the switch block is via a plug connector. will be carried out.

It is an object of the present invention to overcome the limitations and disadvantages of the state of the art and, in particular, to reduce An object of the present invention is to provide a device having reduced cost and improved reliability.

The present invention achieves these objectives by providing a thermocouple and a control switch electrically connected to the thermocouple. one end connected to said control station and the other end terminated in a connector. A contact comprising at least two conductors connected together, mutually insulated and externally shielded. In a device for controlling the temperature of automobile exhaust gas at a central location, the control station The tube is placed in an elongated liquid-tight metal container with two opposed axial passages. and the thermocouple is directly connected to the entrance of the control station through one of the passageways. the conductor is directly connected to the control station and the sealed temperature of the exhaust gas of the automobile, which is discharged from the other passage of the container. Achieved by a device for controlling.

The scope of the claims 1. A thermocouple (1) and a control station (1) electrically connected to the thermocouple. 3), one end is connected to the control station (13) and the other end is connected to the connector ( 4°9), mutually insulated and externally shielded. In a device for controlling the temperature of automobile exhaust gas at the catalyst location including the conductor, the control The control station (13) has two axial passages (5, 6) facing each other. The thermocouple (1) is placed in a long liquid-tight metal container (2), and the thermocouple (1) through one (5) of the control station directly to the entrance of the control station, said conductor being the other of said sealed containers (2) directly connected to said control station (13); A method for controlling the temperature of exhaust gas of an automobile, characterized in that the exhaust gas is discharged from the passage (6). device for

2. The direct connection between the thermocouple and the control station (13) is by inorganic material. In particular, this is done by means of a thermocouple connection cable (15) with an insulator (20). 2. The device of claim 1, wherein:

,, lA-m-N+ PCT/IT 92100062

Claims (8)

[Claims] 1. a thermocouple (1) and a control station (13) electrically connected to said thermocouple; ), one end is connected to the control station (13), and the other end is connected to the connector (4). , 9), mutually insulated and externally shielded. In a device for controlling the temperature of automobile exhaust gas at a catalyst location including a control line, The station (13) is elongated with two opposed axial passages (5, 6). The thermocouple (1) is placed in a liquid-tight metal container (2), and the thermocouple (1) is located in the passageway. through one (5) directly to the inlet of the control station (13) and connected directly to the inlet of the control station (13). The ear is connected directly to the control station (13) and the sealed container (2) Controls the temperature of automobile exhaust gas, characterized in that it exits from the second passage (6) of the equipment for 2. A direct connection between the thermocouple and the control station (13) This is done by a thermocouple connection cable (15) with insulation (20) according to 2. The device of claim 1, characterized in that: 3. The direct connection between the thermocouple (1) and the control station (13) between the thermocouple connection cable (15) insulated by a material and the control station. This is done by a length of shielded cable (7) inserted. 2. The device of claim 1, characterized in that: 4. Said predetermined length of shielded cable (7) and thermocouple insulated case. (15) is made by a metal transition part (8) sealed with resin. 4. Device according to claim 3, characterized in that it is protected by: 5. Car grounding part (21), car battery terminal (+V) that is not grounded, and Provided with at least three conductors (A, B, C) for connection to the warning lamp (23). 5. A device according to claim 1, characterized in that it is provided with: 6. comprising a fourth conductor (D) adapted to be connected to the starting device of the motor vehicle; 6. The device according to claim 5, characterized in that: 7. Said container (2) is made of electroplated steel and has an approximately cylindrical shape. 7. The device according to claim 5 or 6. 8. At the output of the control station, mounted coaxially around said conductor 7. A coil spring (10) according to any one of claims 1 to 6, characterized in that it comprises a coil spring (10). The device described in.