JP6878881B2 - External unit and laser igniter - Google Patents

Description

The present invention relates to an external unit and a laser ignition device.

The laser ignition device is used for igniting an internal combustion engine such as an engine, and is known to obtain excellent ignition efficiency. The laser ignition device includes, for example, a laser ignition plug installed in a plug hole and a light source. This involves irradiating a laser resonator with laser light from a light source to oscillate a pulse, and condensing the pulsed light into the combustion chamber of the engine using an optical element such as a condenser lens to generate air breakdown. , Ignite the air-fuel mixture in the combustion chamber.

When the temperature of the laser medium inside the laser spark plug rises due to the heat from the engine or the heat from the laser beam incident on the laser resonator, the oscillation efficiency decreases and the laser output also decreases. Therefore, the laser spark plug needs to be sufficiently cooled and dissipated.

On the other hand, for example, a laser ignition device provided with means (cooling device) for cooling the laser spark plug for the purpose of cooling the laser medium is known (see Patent Document 1). The laser spark plug of the laser ignition device of Patent Document 1 has a coupling means for mechanical and thermal coupling at an end, and the coupling means is used to connect with a cooler (cooling unit) which is an external unit. It is configured so that it can be connected and disconnected.

In a configuration having a coupling means at the end of the laser ignition plug as in Patent Document 1, heat is absorbed at the position farthest from the two heat sources of heat from the engine and heat generated from the laser medium, so that liquid cooling or the like is performed. Sufficient cooling efficiency cannot be obtained without using a powerful cooler. In particular, the vicinity of the laser medium is a part where heat is generated and also a part through which heat from the engine passes, so that the temperature is higher than that of the surroundings. Therefore, it is desirable to have a configuration in which not only the end portion but the entire laser spark plug is cooled.

However, since the laser spark plug is installed at the bottom of a deep hole such as a plug hole, it is difficult to see it, and a cooling unit (external unit) that contacts the entire laser spark plug to remove heat is desired. It is difficult to confirm whether or not it is installed in the position of. Further, the same problem may occur when an external unit having a function other than the cooling function is attached to a member to be attached such as a laser spark plug.

The present invention has been made in view of the above, and is an external unit capable of confirming whether or not an external unit mounted on a mounted member provided in a place where it is difficult to see is mounted at a desired position. , And a laser igniter is intended to be obtained.

In order to solve the above-mentioned problems and achieve the object, the present invention is inserted into a hole for accommodating a mounted member having a portion at least partially composed of a conductive member, and comes into contact with the mounted member. An external unit to be mounted, the main body portion made of a conductive member, a plurality of sheet-like members provided on the inner wall surface of the main body portion, and the inner wall surface of each of the plurality of sheet-like members. A plurality of contact portions provided in the above, and a continuity detection unit for detecting a state in which the plurality of contact portions are conducting with each other via the portion, and the plurality of sheet-like members are composed of an insulating member. The plurality of contact portions are a plurality of conductive members, and the plurality of contact portions are in an insulated state when the external unit is not mounted on the mounted member, and the external unit is in an insulated state. wherein you contact with the conductive member of the site with fully fitted state with respect to the mounting member.

According to the present invention, it is possible to confirm whether or not the external unit mounted on the mounted member provided in a place where it is difficult to see is mounted at a desired position.

FIG. 1 is a diagram showing an example of a forced ignition type engine (internal combustion engine) using a laser spark plug. FIG. 2 is a diagram showing a state in which the cooling unit is attached to the laser spark plug of the laser ignition device of the first embodiment. FIG. 3 is a horizontal sectional view of X1-X1'of the cooling unit in FIG. 2 (a). FIG. 4 is a flowchart showing the flow of controlling the laser beam by the laser ignition device of the first embodiment. FIG. 5 is a horizontal sectional view of X1-X1'of the cooling unit in FIG. 2A. FIG. 6 is a diagram showing a state in which the cooling unit is attached to the laser spark plug of the laser ignition device of the second embodiment. FIG. 7 is a flowchart showing the flow of controlling the laser beam by the laser ignition device of the second embodiment. FIG. 8 is a diagram showing a state in which the cooling unit is attached to the laser spark plug of the laser ignition device of the third embodiment. FIG. 9 is a horizontal sectional view of X2-X2'of the cooling unit in FIG. 8A. FIG. 10 is a flowchart showing the flow of controlling the laser beam by the laser ignition device of the third embodiment. FIG. 11 is a diagram showing a state in which the external unit is attached to the laser spark plug of the laser ignition device of the modified example of the third embodiment.

An embodiment of the external unit and the laser ignition device will be described in detail with reference to the accompanying drawings.

(First Embodiment)
First, the laser ignition device will be described with reference to FIG. FIG. 1 is a diagram showing an example of a forced ignition type engine (internal combustion engine) using a laser spark plug. As shown in FIG. 1, the laser ignition device 100 includes a laser spark plug 1 and a laser light source 3. The laser spark plug 1 is installed in a deep hole plug hole 2 and is screw-fixed. The laser spark plug 1 corresponds to the mounted member, and the plug hole 2 corresponds to the hole portion.

The laser ignition plug 1 is an ignition plug for an engine having excellent ignition efficiency by using a laser beam emitted from a laser light source 3. As shown in FIG. 1, in the laser ignition plug 1, a laser beam from a laser light source 3 is applied to a Q-switch type laser resonator including a laser medium to oscillate a giant pulse. Then, in the laser spark plug 1, the pulsed light is condensed in the combustion chamber 5 of the engine by using an optical element such as a condenser lens to generate an air breakdown, so that the air-fuel mixture in the combustion chamber 5 is ignited. To operate the engine. An optical fiber 4 for transmitting the laser light emitted from the laser light source 3 is connected to the laser spark plug 1. The laser light source 3 corresponds to the light source.

When operating the engine in this way, in the laser medium of the laser ignition plug 1, of the energy of the laser light emitted from the laser light source 3, the energy that is not output as a giant pulse is converted into heat, and as a result, it is converted into heat. The laser medium generates heat. As a result, when the temperature of the laser medium rises, the oscillation light rate decreases, and a pulsed laser (pulse light) with a desired output may not be excited. Therefore, it is necessary to dissipate heat and cool the laser spark plug 1.

By the way, the laser ignition plug 1 itself is a consumable item, and it is assumed that it will be replaced due to the life of the laser light emitting window due to dirt or deterioration of the laser medium. However, if the cooling / radiating system has a longer life than the laser spark plug 1, the cooling / radiating system should be separated from the laser spark plug 1 so that only the laser spark plug 1 can be replaced at the time of replacement. Is desirable. Therefore, there is a laser ignition device that dissipates heat and cools the laser ignition plug 1 by attaching an external cooling unit to the laser ignition plug 1. The cooling unit corresponds to an external unit.

Here, the problem when mounting the cooling unit, which is an external unit, is that the heat receiving area from the laser spark plug 1 is reduced due to the incomplete mounting state of the cooling unit, and the cooling performance is deteriorated. It is to be. However, in the deep hole plug hole 2, it is difficult to visually recognize the mounting state of the cooling unit with respect to the laser ignition plug 1 provided at the bottom of the plug hole 2. For this reason, it is difficult to notice even if the cooling unit is in an incompletely mounted state, so it is desirable to have a means for recognizing the mounted state of the cooling unit other than visually.

Based on these, the laser ignition device 100 of the present embodiment dissipates and cools the laser ignition plug 1 by attaching an external cooling unit 6 to the laser ignition plug 1, and also cools the laser ignition plug 1. It is configured to be equipped with a means for confirming the mounting state of the laser device other than visually. The details of the laser ignition device 100 of the present embodiment will be described below.

FIG. 2 is a diagram showing a state in which the cooling unit is attached to the laser spark plug of the laser ignition device of the first embodiment.

FIG. 2A shows a state (non-mounted state) before mounting the cooling unit 6 on the laser ignition plug 1. FIG. 2B shows a state in which the cooling unit 6 is being mounted on the laser ignition plug 1 (incomplete mounting state). FIG. 2C shows a state in which the cooling unit 6 is completely mounted on the laser ignition plug 1 (completely mounted state). The position of the cooling unit 6 shown in FIG. 2C is a desired mounting position.

As shown in FIGS. 2A to 2C, the cooling unit 6 is removable from the laser spark plug 1. This facilitates, for example, the work of fixing and removing the laser spark plug 1 with respect to the combustion chamber 5 of the engine. Further, even if it becomes necessary to replace the laser ignition plug 1, the cooling unit 6 can be continuously used without being replaced.

The configuration of the laser ignition device 100 of the first embodiment will be described with reference to FIG. As shown in FIG. 2, the laser ignition device 100 includes a laser light source 3, a laser spark plug 1, a cooling unit 6, and an ignition control unit 110. The laser spark plug 1 is housed in the plug hole 2 (hole) and is fixed to the bottom of the plug hole 2. The cooling unit 6 is inserted into the plug hole 2 accommodating the laser ignition plug 1, and is attached in contact with the laser ignition plug 1. The cooling unit 6 cools the laser spark plug 1 by receiving heat from the laser spark plug 1 and dissipating heat by this contact.

As described above, the laser light source 3 emits the laser light to the laser spark plug 1 (see FIG. 1). The laser light source 3 and the laser spark plug 1 are connected by an optical fiber 4 that transmits the laser light emitted from the laser light source 3.

As described above, the laser spark plug 1 collects the laser light emitted from the laser light source 3 into the combustion chamber 5 to operate the engine (see FIG. 1). The housing of the laser ignition plug 1 of the present embodiment is composed of an upper member 1A having a laser medium inside and a lower member 1B fixed to the combustion chamber 5 of the engine.

Since the upper member 1A holds the YAG crystal and has a function of conducting heat from the YAG crystal toward the external cooling unit 6, it is made of a material having higher thermal conductivity than the lower member 1B. And at least its surface is insulating. For example, the upper member 1A of the present embodiment uses aluminum whose surface is anodized. As a result, the surface of the upper member 1A can be insulated by alumite while taking advantage of the high thermal conductivity of aluminum. The upper member 1A corresponds to the second portion.

The lower member 1B is composed of a conductive member that is conductive. Since it is preferable that the lower member 1B fixed to the combustion chamber 5 side of the engine (see FIG. 1) does not transfer the heat from the engine to the YAG crystal, the lower member 1B is hotter than the upper member 1A, for example, like stainless steel. It is composed of a material with low conductivity. The lower member 1B corresponds to the first portion.

The cooling unit 6 includes a heat sink 6A, two heat pipes 6B1 and 6B2, and a mounting portion 6C including heat receiving members 6C1 and 6C2. When the cooling unit 6 is mounted on the laser spark plug 1, the heat generated from the laser spark plug 1 is received by the heat receiving members 6C1 and 6C2 of the mounting portion 6C. Then, the heat is transferred to the heat sink 6A by the heat pipes 6B1 and 6B2, and the heat sink 6A dissipates heat outside the plug hole 2 to cool the laser spark plug 1.

The heat receiving members 6C1 and 6C2 are made of a conductive member such as copper or aluminum. Then, when the cooling unit 6 is mounted on the laser spark plug 1, the heat receiving members 6C1 and 6C2 come into contact with the surfaces of the upper member 1A and the lower member 1B, which are the housings of the laser ignition plug 1, and the heat receiving members 6C1 and 6C2 come into contact with the surfaces of the laser ignition plug 1 from the laser ignition plug 1. Receives the heat generated by.

Here, the configuration of the mounting portion 6C will be described. FIG. 3 is a horizontal sectional view of X1-X1'of the cooling unit in FIG. 2 (a). In FIG. 3, configurations other than the cooling unit 6 such as the optical fiber 4 are omitted.

As shown in FIG. 3, the mounting portion 6C has a heat receiving members 6C1 and 6C2 and a connecting portion 6C3 connecting the heat receiving members 6C1 and 6C2, and a cylinder having a gap D1 between the heat receiving members 6C1 and 6C2. It is formed in a shape. The connecting portion 6C3 is made of an insulating member such as resin, and is configured so that the heat receiving members 6C1 and 6C2 are not connected. The heat receiving members 6C1 and 6C2 are made of conductive members as described above. When the cooling unit 6 is mounted on the laser ignition plug 1, the mounting portion 6C is mounted in contact with the surface of the laser ignition plug 1.

Further, as shown in FIG. 3, the heat pipes 6B1 and 6B2 are provided so as to penetrate through the heat receiving members 6C1 and 6C2, respectively. As a result, the heat absorbed by the heat receiving members 6C1 and 6C2 is transferred to the heat sink 6A by the heat pipes 6B1 and 6B2, and is dissipated.

In the configuration of the mounting portion 6C shown in FIG. 3, the heat receiving members 6C1 and 6C2 correspond to a plurality of contact portions. Since the heat receiving members 6C1 and 6C2 do not have contacts due to the provision of the connecting portion 6C3 and the gap D1, the cooling unit 6 is in an insulated state when the cooling unit 6 is not attached to the laser spark plug 1. Then, when the cooling unit 6 is completely attached to the laser ignition plug 1, the heat receiving members 6C1 and 6C2 come into contact with the lower member 1B made of the conductive member, so that the heat receiving members 6C1 and 6C2 attach the lower member 1B. It becomes a conductive state through.

Returning to FIG. 2, the ignition control unit 110 controls the laser light source 3 based on the presence or absence of continuity of the heat receiving members 6C1 and 6C2, which are a plurality of contact parts. The ignition control unit 110 of the present embodiment is, for example, a control circuit constructed by hardware such as an IC, but is not limited to this, and is realized by executing a program having a CPU, ROM, RAM, or the like. It may be configured to be used. The ignition control unit 110 functions as a continuity detection unit 111, a light source control unit 112, and a notification unit 113 by executing a control circuit or a program.

The continuity detection unit 111 passes a weak current through the heat receiving members 6C1 and 6C2, and when the heat receiving members 6C1 and 6C2 of the laser ignition plug 1 come into contact with the lower member 1B of the cooling unit 6 (FIG. 2C), the heat receiving member A state in which 6C1 and 6C2 are conducting with each other via the lower member 1B is detected. In this way, when the heat receiving members 6C1 and 6C2 are in a conductive state, it can be confirmed that the laser spark plug 1 is mounted at a desired position with respect to the cooling unit 6.

Further, in the continuity detection unit 111, even if a weak current is passed through the heat receiving members 6C1 and 6C2, the heat receiving members 6C1 and 6C2 of the laser ignition plug 1 are not in contact with the lower member 1B of the cooling unit 6 (FIG. 2 (FIG. 2). a) (b)), the state in which the heat receiving members 6C1 and 6C2 are conducting cannot be detected.

Here, with reference to FIG. 2, a case where the cooling unit 6 which is an external unit is attached to the laser ignition plug 1 will be described from above the laser ignition plug 1. As described above, the heat receiving members 6C1, 6C2 and the lower member 1B are made of a conductive member, and the upper member 1A is made of a member having an insulating surface.

As shown in FIG. 2A, before the cooling unit 6 is attached to the laser ignition plug 1, that is, in the non-attached state, the heat receiving members 6C1 and 6C2 are the upper member 1A and the lower member 1B of the laser ignition plug 1. It does not come into contact with any of them and is in an insulated state. Therefore, even if a weak current is passed through the heat receiving members 6C1 and 6C2 in this state, the continuity detecting unit 111 cannot detect the continuity between the heat receiving members 6C1 and 6C2 and can recognize that it is in an insulated state. From this, it can be confirmed that the cooling unit 6 is not mounted at a desired position with respect to the laser ignition plug 1.

Next, when the cooling unit 6 which is an external unit is inserted from above the laser ignition plug 1, the state as shown in FIG. 2B, that is, the incompletely mounted state is obtained. Even if a weak current is passed through the heat receiving members 6C1 and 6C2 in this state, the upper member 1A made of a member having an insulating surface is sandwiched between the heat receiving members 6C1 and 6C2, so that the upper member 1A does not conduct and is insulated. The state is maintained. Therefore, the continuity detection unit 111 cannot detect the continuity between the heat receiving members 6C1 and 6C2 and can recognize that it is in an insulated state, as in FIG. 2A. From this, it can be confirmed that the cooling unit 6 is not mounted at a desired position with respect to the laser ignition plug 1.

Then, when the cooling unit 6 is further inserted, the state as shown in FIG. 2C, that is, the completely mounted state is obtained. When a weak current is passed through the heat receiving members 6C1 and 6C2 in this state, the lower member 1B made of a conductive member is sandwiched between the heat receiving members 6C1 and 6C2, so that the lower member 1B becomes conductive via the lower member 1B. .. Therefore, the continuity detection unit 111 can detect the continuity between the heat receiving members 6C1 and 6C2, and can recognize that the continuity is in the conduction state. From this, it can be confirmed that the cooling unit 6 is mounted at a desired position with respect to the laser ignition plug 1.

In this way, the continuity detection unit 111 allows a weak current to flow through the heat receiving members 6C1 and 6C2, and the mounting state of the cooling unit 6 can be recognized depending on the presence or absence of detection of continuity between the heat receiving members 6C1 and 6C2 (detection result). That is, if the continuity cannot be detected, it is in the non-mounted state or the incompletely mounted state, and if the continuity can be detected, it can be recognized that it is in the fully mounted state.

The light source control unit 112 controls the laser light source 3 that emits laser light based on the detection result by the continuity detection unit 111. That is, when the light source control unit 112 detects that the heat receiving members 6C1 and 6C2 are conducting with each other by the continuity detection unit 111, the laser ignition plug 1 is completely attached to the cooling unit 6 (FIG. 2 (c). )) Is determined, and the laser light is controlled to be emitted from the laser light source 3.

On the other hand, when the light source control unit 112 does not detect that the heat receiving members 6C1 and 6C2 are conducting with each other by the continuity detection unit 111, the laser ignition plug 1 is not or incompletely attached to the cooling unit 6. It is determined that the state (FIGS. 2A and 2B), and control is performed so that the laser light is not emitted from the laser light source 3.

The light source control unit 112 determines that the laser ignition plug 1 is not attached or incompletely attached to the cooling unit 6 (FIGS. 2A and 2B), and the notification unit 113 emits laser light. If not, it notifies the user to wear it completely. The notification means, for example, turning on or blinking a lamp, or outputting a warning sound from a speaker.

Next, the flow of controlling the laser beam by the laser ignition device 100 will be described. FIG. 4 is a flowchart showing the flow of controlling the laser beam by the laser ignition device of the first embodiment.

First, when the cooling unit 6 is attached to the laser ignition plug 1 by the user and the power of the laser ignition device 100 is turned on, the continuity detection unit 111 passes a weak current through the heat receiving members 6C1 and 6C2 (step S10).

The light source control unit 112 determines whether or not the continuity detection unit 111 has detected a state in which the heat receiving members 6C1 and 6C2 are conducting (step S11). When a state in which the heat receiving members 6C1 and 6C2 are conducting is detected (step S11: Yes), the light source control unit 112 is in a state where the laser ignition plug 1 is completely attached to the cooling unit 6 (FIG. 2C). Is determined, and the laser light is controlled to be emitted from the laser light source 3 (step S12).

On the other hand, when the state in which the heat receiving members 6C1 and 6C2 are conducting is not detected (step S11: No), the light source control unit 112 is incompletely attached with the laser spark plug 1 to the cooling unit 6 (FIG. 2). (B)) is determined, and control is performed so that the laser beam of the laser light source 3 is not emitted (step S13). Then, the notification unit 113 notifies the user to urge the user to wear the product completely (step S14).

As described above, the laser ignition device 100 of the first embodiment is conductive to the laser spark plug 1 having the upper member 1A made of a member having an insulating surface and the lower member 1B made of a conductive member. An external cooling unit 6 having heat receiving members 6C1 and 6C2 composed of sex members is attached. Then, a weak current is passed through the heat receiving members 6C1 and 6C2, and when the cooling unit 6 is completely mounted on the laser ignition plug 1, the lower member 1B is sandwiched between the heat receiving members 6C1 and 6C2, so that the conduction state can be detected. Thereby, it can be confirmed by a method other than visual inspection whether or not the cooling unit 6 mounted on the laser ignition plug 1 provided in a place where it is difficult to see is mounted at a desired position.

Further, the laser ignition device 100 of the first embodiment emits laser light from the laser light source 3 when the continuity between the heat receiving members 6C1 and 6C2 cannot be detected, that is, when the cooling unit 6 is incompletely mounted. By not doing so, it is possible to prevent an abnormal temperature rise due to an incomplete cooling state and a failure of the laser ignition plug 1 due to the abnormal temperature rise. Further, when the cooling unit 6 is in an incompletely mounted state and does not emit laser light, the user is notified that the cooling unit 6 is in an incompletely mounted state by notifying the user that the cooling unit 6 is in an incompletely mounted state. be able to.

Further, since the laser ignition device 100 of the first embodiment has the above-described configuration, it controls by the presence or absence of energization without providing an electric connector or the like, so that it can be controlled more directly with a simple mechanism. The contact state between the laser ignition plug 1 and the cooling unit 6 can be determined.

(Modified example of the first embodiment)
The mounting portion 6C of the first embodiment has the heat receiving members 6C1 and 6C2 and the connecting portion 6C3, and is formed in a cylindrical shape in which a gap D1 is provided between the heat receiving members 6C1 and 6C2. Part 6C may be configured as follows.

FIG. 5 is a horizontal sectional view of X1-X1'of the cooling unit in FIG. 2A. Note that in FIG. 5, configurations other than the cooling unit 6, such as the optical fiber 4, are omitted.

The mounting portion 6C shown in FIG. 5A has a heat receiving member 6C4, sheet-shaped members 6D1 and 6D2, and electrode plates 6E1 and 6E2, and a gap D1 is provided between the ends of the heat receiving member 6C4. It is formed in a cylindrical shape. Sheet-shaped members 6D1 and 6D2 made of an insulating member such as resin are provided on the inner wall surface of the heat receiving member 6C4. Further, electrode plates 6E1 and 6E2, which are conductive members, are provided on the inner wall surfaces of the sheet-shaped members 6D1 and 6D2, respectively. Further, the heat receiving member 6C4 is composed of the conductive member as described above. When the cooling unit 6 is mounted on the laser ignition plug 1, the mounting portion 6C is mounted in contact with the surface of the laser ignition plug 1. Although the present embodiment has a configuration in which two electrode plates are provided, a configuration in which three or more electrode plates are provided may be provided.

Further, as shown in FIG. 5A, the heat pipes 6B1 and 6B2 are provided so as to penetrate the heat receiving member 6C4. As a result, the heat absorbed by the heat receiving member 6C4 is transferred to the heat sink 6A by the heat pipes 6B1 and 6B2, and is dissipated.

In such a configuration example of FIG. 5A, the heat receiving member 6C4 corresponds to the main body portion, and the electrode plates 6E1 and 6E2 correspond to a plurality of contact portions. Since the electrode plates 6E1 and 6E2 have no contacts because they are provided on the sheet-shaped members 6D1 and 6D2 made of insulating members, respectively, the cooling unit 6 is in an insulated state when it is not attached to the laser spark plug 1. .. When the cooling unit 6 is attached to the laser ignition plug 1, the electrode plates 6E1 and 6E2 come into contact with the lower member 1B made of a conductive member, so that the electrode plates 6E1 and 6E2 are conductive via the lower member 1B. It becomes a state.

As another example, the mounting portion 6C shown in FIG. 5B is a heat receiving members 6C1 and 6C2, and is formed in a cylindrical shape in which gaps D1 and D2 are provided between the heat receiving members 6C1 and 6C2. When the cooling unit 6 is mounted on the laser spark plug 1, the heat receiving members 6C1 and 6C2, which are the mounting portions 6C, are mounted in contact with the surface of the laser spark plug 1.

Further, as shown in FIG. 5B, the heat pipes 6B1 and 6B2 are provided so as to penetrate the heat receiving members 6C1 and 6C2, respectively. As a result, the heat absorbed by the heat receiving members 6C1 and 6C2 is transferred to the heat sink 6A by the heat pipes 6B1 and 6B2 and dissipated.

In such a configuration example of FIG. 5B, the heat receiving members 6C1 and 6C2 correspond to a plurality of contact portions and correspond to a mounting portion. Since the heat receiving members 6C1 and 6C2 do not have contacts due to the provision of the gaps D1 and D2, the cooling unit 6 is in an insulated state when the laser ignition plug 1 is not attached. When the cooling unit 6 is attached to the laser ignition plug 1, the heat receiving members 6C1 and 6C2 come into contact with the lower member 1B made of the conductive member, so that the heat receiving members 6C1 and 6C2 are electrically connected via the lower member 1B. It becomes a state.

Even when the mounting portion 6C is configured in this way, the same effect as that of the first embodiment is obtained. Further, in the present embodiment, the configuration examples (FIGS. 3 and 5 (a) and 5 (b)) of the above-mentioned three mounting portions 6C have been described, but the present invention is not limited thereto.

(Second embodiment)
In the laser ignition device of the first embodiment, a cooling unit for cooling the laser spark plug is attached to the laser ignition plug, but it is also possible to attach an external unit having other functions. Good. Therefore, the laser ignition device of the present embodiment is further configured to have a temperature detection function for detecting the temperature of the laser spark plug in the cooling unit. The same parts as those in the first embodiment described above are indicated by the same reference numerals, and the description thereof will be omitted.

By using such an imparting function as an external unit, the workability of assembling the laser spark plug 1 to the engine is improved. That is, since the laser spark plug 1 is screw-fixed to the engine, it is necessary to rotate the shaft at the time of fixing. Therefore, if the main body of the laser spark plug 1 is provided with a control means or the like connected by a cable or the like, the handling of those cables becomes very complicated when the laser spark plug 1 is fixed. Therefore, the laser spark plug 1 has a simple structure as much as possible to facilitate the workability of mounting on the engine, and the imparting function can be easily mounted as an external unit to reduce the above complexity. It can be avoided.

Hereinafter, a laser ignition device having a temperature detection function for detecting the temperature of the laser spark plug will be described. Even in the case of an external unit having a temperature detection function for monitoring the operating temperature state of such a laser spark plug, in order to accurately detect the temperature, the external unit is in a completely mounted state (desired). It is desirable to be in the position of). Therefore, the laser ignition device of the present embodiment also has a configuration capable of confirming the mounting position of the external unit as in the first embodiment.

The configuration of the engine is the same as that of the first embodiment (see FIG. 1). FIG. 6 is a diagram showing a state in which the cooling unit is attached to the laser spark plug of the laser ignition device of the second embodiment. The laser spark plug 1 corresponds to the mounted member.

FIG. 6A shows a state (non-mounted state) before the cooling unit 61 is mounted on the laser ignition plug 1. FIG. 6B shows a state in which the cooling unit 61 is being mounted on the laser ignition plug 1 (incomplete mounting state). FIG. 6C shows a state in which the cooling unit 61 is completely mounted on the laser ignition plug 1 (completely mounted state). The position of the cooling unit 61 shown in FIG. 6C is a desired mounting position.

The configuration of the laser ignition device 200 of the second embodiment will be described with reference to FIG. As shown in FIG. 6, the laser ignition device 200 includes a laser light source 3, a laser spark plug 1, a cooling unit 61, and an ignition control unit 210. The laser spark plug 1 is housed in the plug hole 2 (hole) and is fixed to the bottom of the plug hole 2. The cooling unit 61 is inserted into the plug hole 2 accommodating the laser ignition plug 1, and is attached in contact with the laser ignition plug 1. The cooling unit 61 cools the laser spark plug 1 by receiving heat from the laser spark plug 1 and dissipating heat by this contact. Here, since the laser light source 3 and the laser spark plug 1 are the same as those in the first embodiment, the description thereof will be omitted.

The cooling unit 61 includes a heat sink 6A, two heat pipes 6B1 and 6B2, a mounting portion 6C including heat receiving members 6C1 and 6C2, and a temperature sensor 7. Here, the heat sink 6A, the heat pipes 6B1, 6B2, and the mounting portion 6C are the same as those in the first embodiment. Therefore, it is possible to apply a plurality of configuration examples (FIGS. 3, 5 (a), (b), etc.) to the mounting portion 6C.

The temperature sensor 7 is provided on the inner wall surface side of the heat receiving member 6C1, and when the cooling unit 61 is completely mounted (see FIG. 6C), the temperature sensor 7 comes into contact with the upper member 1A of the laser spark plug 1 to make a laser. Detects the heat of the spark plug 1. The detection signal by the temperature sensor 7 is sent to the temperature detection unit 214, which will be described later.

The ignition control unit 210 controls the laser light source 3 based on the presence or absence of continuity of the heat receiving members 6C1 and 6C2, which are a plurality of contact parts, and the temperature of the laser spark plug 1. The ignition control unit 210 of the present embodiment is, for example, a control circuit constructed by hardware such as an IC, but is not limited to this, and is realized by executing a program having a CPU, ROM, RAM, or the like. It may be configured to be used. The ignition control unit 210 functions as a continuity detection unit 111, a temperature detection unit 214, a light source control unit 212, and a notification unit 113 by executing a control circuit or a program. Here, the continuity detection unit 111 and the notification unit 113 are the same as those in the first embodiment, and thus the description thereof will be omitted.

The temperature detection unit 214 detects the temperature of the laser ignition plug 1 based on the detection signal received from the temperature sensor 7.

The light source control unit 212 controls the laser light source 3 that emits laser light based on the detection result by the continuity detection unit 111. That is, when the light source control unit 212 detects that the heat receiving members 6C1 and 6C2 are conducting with each other by the continuity detection unit 111, the laser ignition plug 1 is completely attached to the cooling unit 61 (FIG. 6 (c). )) Is determined, and the laser light is controlled to be emitted from the laser light source 3.

On the other hand, in the light source control unit 212, when the continuity detection unit 111 does not detect a state in which the heat receiving members 6C1 and 6C2 are conducting, the laser ignition plug 1 is not or incompletely attached to the cooling unit 61. It is determined that the state (FIGS. 6A and 6B), and control is performed so that the laser beam is not emitted from the laser light source 3.

Further, in the light source control unit 212, when the laser ignition plug 1 is completely attached to the cooling unit 61 (FIG. 6 (c)), the temperature detected by the temperature detection unit 214 is equal to or lower than the predetermined temperature. If so, the laser light source 3 is controlled to emit the laser beam. On the other hand, even when the laser ignition plug 1 is completely attached to the cooling unit 61 (FIG. 6 (c)), the light source control unit 212 causes the detected temperature to rise abnormally due to an abnormal temperature rise or the like. When the temperature exceeds a predetermined temperature, control is performed so that the laser beam of the laser light source 3 is not emitted. The predetermined temperature can be set arbitrarily.

Here, as described above, when detecting the temperature of the laser ignition plug 1, if the cooling unit 61 is incompletely mounted (FIG. 6B), the temperature sensor 7 can come into contact with the laser ignition plug 1. Since accurate temperature detection may not be possible, the laser light source 3 is controlled by the temperature detected when the cooling unit 61 is fully mounted (FIG. 6 (c)).

Next, the flow of controlling the laser beam by the laser ignition device 200 will be described. FIG. 7 is a flowchart showing the flow of controlling the laser beam by the laser ignition device of the second embodiment.

First, when the cooling unit 61 is attached to the laser ignition plug 1 by the user and the power of the laser ignition device 200 is turned on, the continuity detection unit 111 passes a weak current through the heat receiving members 6C1 and 6C2 (step S30).

The light source control unit 212 determines whether or not the continuity detection unit 111 has detected a state in which the heat receiving members 6C1 and 6C2 are conducting (step S31). When a state in which the heat receiving members 6C1 and 6C2 are conducting is detected (step S31: Yes), the light source control unit 212 determines whether or not the laser spark plug 1 has a temperature equal to or higher than a predetermined temperature (step S32).

When the laser spark plug 1 is below the predetermined temperature (step S32: No), the light source control unit 212 determines that the laser spark plug 1 is completely attached to the cooling unit 61 (FIG. 6 (c)). , Control to emit the laser beam from the laser light source 3 (step S33).

On the other hand, when the state in which the heat receiving members 6C1 and 6C2 are conducting is not detected in step S31 (step S31: No), the light source control unit 212 has an incomplete laser spark plug 1 with respect to the cooling unit 61. It is determined that the laser light source 3 is mounted (FIG. 6B), and control is performed so that the laser beam of the laser light source 3 is not emitted (step S34). Then, the notification unit 113 notifies the user to completely wear the device (step S35).

Further, in step S32, when the laser ignition plug 1 has a temperature equal to or higher than a predetermined temperature (step S32: Yes), the light source control unit 212 controls not to emit the laser light of the laser light source 3 (step S36).

The laser ignition device 200 described above has a configuration in which the cooling unit 61 is provided with a temperature detection function, but it is possible to sufficiently dissipate heat generated from the laser ignition plug 1 and cool it by a method other than the external unit. In this case, an external unit (temperature detection unit) that does not have a heat dissipation / cooling system and has only a temperature detection function may be provided.

As described above, the laser ignition device 200 of the second embodiment is conductive to the laser spark plug 1 having the upper member 1A made of a member having an insulating surface and the lower member 1B made of a conductive member. An external cooling unit 61 having heat receiving members 6C1 and 6C2 composed of sex members is attached. Then, when a weak current is passed through the heat receiving members 6C1 and 6C2 and the cooling unit 61 is completely mounted on the laser ignition plug 1, the lower member 1B is sandwiched between the heat receiving members 6C1 and 6C2, so that the conduction state can be detected. Thereby, it can be confirmed by a method other than visual inspection whether or not the cooling unit 61 mounted on the laser ignition plug 1 provided in a place where it is difficult to see is mounted at a desired position.

Further, in the laser ignition device 200 of the second embodiment, when the continuity between the heat receiving members 6C1 and 6C2 cannot be detected, that is, when the cooling unit 61 is incompletely mounted or the cooling unit 61 is completely mounted. However, when the temperature of the laser ignition plug 1 is equal to or higher than a predetermined temperature, the laser light from the laser light source 3 is not emitted, so that the laser ignition plug 1 is abnormally heated due to an incomplete cooling state or the abnormal temperature rise. It is possible to prevent the failure of the laser. Further, when the cooling unit 61 is in an incompletely mounted state and does not emit laser light, the user is notified that the cooling unit 61 is in an incompletely mounted state by notifying the user that the cooling unit 61 is completely mounted. be able to.

Further, since the laser ignition device 200 of the second embodiment has the above-described configuration, it controls by the presence or absence of energization without providing an electric connector or the like, so that it can be controlled more directly with a simple mechanism. The contact state between the laser ignition plug 1 and the cooling unit 61 can be determined.

(Third Embodiment)
The laser ignition device of the first embodiment has a configuration in which a cooling unit for cooling the laser ignition plug is attached to the laser ignition plug. The laser ignition device of the second embodiment has a configuration in which the cooling unit is further provided with a temperature detection function for detecting the temperature of the laser ignition plug. On the other hand, the laser ignition device of the present embodiment has a configuration in which the cooling unit is provided with a laser detection function for detecting the generation of laser light by the laser spark plug. The same parts as those in the first embodiment described above are indicated by the same reference numerals, and the description thereof will be omitted.

Even in the case of an external unit equipped with a laser detection function for monitoring the state of generation of laser light in such a laser spark plug, the external unit is completely mounted in order to accurately detect the laser light. It is desirable to be in a state (desired position). Therefore, the laser ignition device of the present embodiment also has a configuration capable of confirming the mounting position of the external unit as in the first embodiment.

The configuration of the engine is the same as that of the first embodiment (see FIG. 1). FIG. 8 is a diagram showing a state in which the cooling unit is attached to the laser spark plug of the laser ignition device of the third embodiment. The laser spark plug 12 corresponds to the mounted member.

FIG. 8A shows a state (non-mounted state) before the cooling unit 62 is mounted on the laser ignition plug 12. FIG. 8B shows a state in which the cooling unit 62 is being mounted on the laser ignition plug 12 (incomplete mounting state). FIG. 8C shows a state in which the cooling unit 62 is completely mounted on the laser ignition plug 12 (fully mounted state). The position of the cooling unit 62 shown in FIG. 8C is a desired mounting position.

The configuration of the laser ignition device 300 of the third embodiment will be described with reference to FIG. As shown in FIG. 8, the laser ignition device 300 includes a laser light source 3, a laser spark plug 12, a cooling unit 62, and an ignition control unit 310. The laser spark plug 12 is housed in the plug hole 2 (hole) and is fixed to the bottom of the plug hole 2. The cooling unit 62 is inserted into the plug hole 2 accommodating the laser ignition plug 12, and is attached in contact with the laser ignition plug 12. The cooling unit 62 cools the laser spark plug 12 by receiving heat from the laser spark plug 12 and dissipating heat by this contact. Here, since the laser light source 3 is the same as that of the first embodiment, the description thereof will be omitted.

The laser spark plug 12 has a configuration in which a window portion 9 is added to the laser spark plug 12 according to the first embodiment. Therefore, the configurations other than the window portion 9 (upper member 1A, lower member 1B, etc.) are the same as those in the first embodiment, and thus the description thereof will be omitted.

The window portion 9 is a window provided above the lower member 1B and at a position where the inside of the laser ignition plug 12 can be seen. The window portion 9 is provided on the engine side of the YAG crystal in order to optically detect the laser light output by the Q switch contained in the YAG crystal held in the upper member 1A.

The cooling unit 62 includes a heat sink 6A, two heat pipes 6B1 and 6B2, a mounting portion 6C including heat receiving members 6C1 and 6C2, and a photodiode 8. Here, the heat sink 6A, the heat pipes 6B1, 6B2, and the mounting portion 6C are the same as those in the first embodiment. Therefore, it is possible to apply a plurality of configuration examples (FIGS. 3, 5 (a), (b), etc.) to the mounting portion 6C.

The photodiode 8 is provided in the lower part of the heat receiving member 6C1 and senses a part of the pulsed light from the window portion 9 provided in the laser spark plug 12 by the light receiving element to detect the pulsed light. The detection signal by the photodiode 8 is sent to the photodetector 315, which will be described later. As a result, it is possible to detect the generation of laser light by the Q switch contained in the YAG crystal of the laser spark plug 12, and it is possible to confirm whether or not the pulsed light is excited. The photodiode 8 is an example of a photodetector.

Since the photodiode 8 detects the laser beam through the window portion 9, when the cooling unit 62 is mounted in the fully mounted state (FIG. 8C) at a desired position with respect to the laser ignition plug 12. , The photodiode 8 is provided at a position where it faces and contacts the window portion 9. Therefore, when the cooling unit 62 is incompletely mounted (FIG. 8B), the position of the photodiode 8 deviates from the position of the window portion 9, and the laser beam cannot be detected.

Further, in the laser ignition device 300 of the present embodiment, when the inner walls of the laser ignition plug 12 and the cooling unit 62 are formed in a cylindrical shape, even if the cooling unit 62 is pushed all the way in and reaches the complete mounting position, There is a possibility that the photodiode 8 and the window portion 9 are displaced in the circumferential rotation direction of the cylinder and are not aligned with each other. Therefore, it is desirable that the photodiode 8 has a shape that can be fixed without rotating, that is, so that the photodiode 8 does not shift with respect to the window portion 9.

Here, an example of a shape in which the photodiode 8 does not rotate with respect to the window portion 9 will be described with reference to FIG. FIG. 9 is a horizontal sectional view of X2-X2'of the cooling unit in FIG. 8A. In FIG. 9, the configuration other than the cooling unit 62 such as the optical fiber 4 and the inside of the laser spark plug 12 are omitted.

FIG. 9A shows a configuration in which a key groove is provided in the photodiode 8 and the window portion 9. As shown in FIG. 9A, a groove 1D is formed in the laser spark plug 12. On the other hand, a protrusion 6C5 that engages with the groove 1D is formed on the mounting portion 6C of the cooling unit 62. Then, when the cooling unit 62 is mounted, the protrusion 6C5 engages with the groove 1D. This makes it possible to prevent the cooling unit 62 from rotating with respect to the laser spark plug 12.

FIG. 9B shows a configuration in which the photodiode 8 and the window portion 9 are formed in a D-cut shape. As shown in FIG. 9B, a part of the circumference of the laser ignition plug 12 is formed in the linear shape portion 1E. On the other hand, the mounting portion 6C of the cooling unit 62 is formed with a linearly shaped portion 6C6 that comes into contact with the linearly shaped portion 1E. Then, the cooling unit 62 is mounted at a position where the linear shape portion 6C6 comes into contact with the linear shape portion 1E. This makes it possible to prevent the cooling unit 62 from rotating with respect to the laser spark plug 12.

The ignition control unit 310 controls the laser light source 3 based on the presence or absence of continuity of the heat receiving members 6C1 and 6C2, which are a plurality of contact parts, and the generation state of the laser beam. The ignition control unit 310 of the present embodiment is, for example, a control circuit constructed by hardware such as an IC, but is not limited to this, and is realized by executing a program having a CPU, ROM, RAM, or the like. It may be configured to be used. The ignition control unit 310 functions as a continuity detection unit 111, a light detection unit 315, a light source control unit 312, and a notification unit 113 by executing a control circuit or a program. Here, the continuity detection unit 111 is the same as that of the first embodiment, and thus the description thereof will be omitted.

The photodetector 315 detects the generation of laser light by the Q switch included in the YAG crystal of the laser spark plug 12 based on the detection signal received from the photodiode 8.

The light source control unit 312 controls the laser light source 3 that emits laser light based on the detection result by the continuity detection unit 111. That is, when the light source control unit 312 detects that the heat receiving members 6C1 and 6C2 are conducting with each other by the continuity detection unit 111, the laser ignition plug 12 is completely attached to the cooling unit 62 (FIG. 8 (c). )) Is determined, and the laser light is controlled to be emitted from the laser light source 3.

On the other hand, when the light source control unit 312 does not detect that the heat receiving members 6C1 and 6C2 are conducting with each other by the continuity detection unit 111, the laser ignition plug 12 is not or incompletely attached to the cooling unit 62. It is determined that the state (FIGS. 8A and 8B), and control is performed so that the laser beam is not emitted from the laser light source 3.

Further, the light source control unit 312 is in a state where the laser ignition plug 12 is completely attached to the cooling unit 62 (FIG. 8 (c)), and when a normal laser beam is detected by the light detection unit 315. , Control to continuously emit laser light from the laser light source 3. On the other hand, even when the laser ignition plug 12 is completely attached to the cooling unit 62 (FIG. 8 (c)), the light source control unit 312 does not detect normal laser light, the laser light source 3 Controls to stop the emission of the laser beam.

Here, as described above, when the generation of the laser beam from the laser ignition plug 12 is detected and the cooling unit 62 is in an incompletely mounted state (FIG. 8B), the photodiode 8 is the window portion 9. The laser light source 3 is controlled based on the laser beam detected when the cooling unit 62 is in the fully mounted state (FIG. 8 (c)) because the laser beam may not be detected accurately. ..

Next, the flow of controlling the laser beam by the laser ignition device 300 will be described. FIG. 10 is a flowchart showing the flow of controlling the laser beam by the laser ignition device of the third embodiment.

First, when the cooling unit 62 is attached to the laser ignition plug 12 by the user and the power of the laser ignition device 300 is turned on, the continuity detection unit 111 passes a weak current through the heat receiving members 6C1 and 6C2 (step S50).

The light source control unit 312 determines whether or not the continuity detection unit 111 has detected a state in which the heat receiving members 6C1 and 6C2 are conducting (step S51). When a state in which the heat receiving members 6C1 and 6C2 are conducting is detected (step S51: Yes), the light source control unit 312 is in a state where the laser ignition plug 12 is completely attached to the cooling unit 62 (FIG. 8C). Is determined, and the laser light is controlled to be emitted from the laser light source 3 (step S52).

On the other hand, when the state in which the heat receiving members 6C1 and 6C2 are conducting is not detected (step S51: No), the light source control unit 312 is incompletely attached with the laser spark plug 12 to the cooling unit 62 (FIG. 8). (B)) is determined, and control is performed so that the laser beam of the laser light source 3 is not emitted (step S53). Then, the notification unit 113 notifies the user to urge the user to wear it completely (step S54).

Next, the light source control unit 312 determines whether or not the light detection unit 315 has detected a normal laser beam (step S55). When a normal laser beam is detected (step S55: Yes
), Control is performed to continuously emit the laser beam from the laser light source 3. On the other hand, when a normal laser beam is not detected (step S55: No), control is performed to stop the emission of the laser beam from the laser light source 3 (step S56).

As described above, the laser ignition device 300 of the third embodiment is conductive to the laser spark plug 12 having the upper member 1A made of a member having an insulating surface and the lower member 1B made of a conductive member. An external cooling unit 62 having heat receiving members 6C1 and 6C2 composed of sex members is attached. Then, when a weak current is passed through the heat receiving members 6C1 and 6C2 and the cooling unit 62 is completely mounted on the laser ignition plug 12, the lower member 1B is sandwiched between the heat receiving members 6C1 and 6C2, so that the conduction state can be detected. Thereby, it can be confirmed by a method other than visual inspection whether or not the cooling unit 62 mounted on the laser ignition plug 12 provided in a place where it is difficult to see is mounted at a desired position.

Further, the laser ignition device 300 of the third embodiment is provided with a laser detection function for detecting the generation state of the laser light in the laser ignition plug 12, so that when a laser light ignition failure occurs, the YAG crystal is used. Since it is possible to determine whether the cause is poor excitation or other causes (for example, dirt on the optical element or window), the cause can be isolated. Then, the laser ignition device 300 of the third embodiment controls not to emit the laser light from the laser light source 3 when the cooling unit 62 is incompletely mounted. As a result, it is possible to prevent an abnormal temperature rise due to an incomplete cooling state and a failure of the laser ignition plug 12 due to the abnormal temperature rise. Further, in the laser ignition device 300 of the third embodiment, when a normal laser beam cannot be detected from the laser ignition plug 12 even when the cooling unit 62 is completely mounted, the laser beam is emitted from the laser light source 3. Stop operation. As a result, it is possible to recognize the failure of the laser ignition plug 12 due to the fact that the normal laser beam is not emitted. Further, when the cooling unit 62 is in an incompletely mounted state and does not emit laser light, the user is notified that the cooling unit 62 is in an incompletely mounted state by notifying the user that the cooling unit 62 is in an incompletely mounted state. be able to.

Further, since the laser ignition device 300 of the third embodiment has the above-described configuration, it controls by the presence or absence of energization without providing an electric connector or the like, so that it can be controlled more directly with a simple mechanism. The contact state between the laser ignition plug 12 and the cooling unit 62 can be determined.

Here, in the present embodiment, in order to recognize the generation state of the laser beam in the laser ignition plug 12, the photodiode 8 has a function of sensing and detecting the pulsed light from the Q switch. , It is also possible to recognize the generation state of the laser beam by other configurations.

For example, by providing a microphone instead of a photodiode in the cooling unit 62 and detecting the sound when the pulsed light is excited by the Q switch or when the air breaks down in the combustion chamber 5 (see FIG. 1), the laser light can be emitted. It may be configured to recognize the generation state. In the case of such a configuration, since it is necessary to be as close as possible to the sound source, it is desirable that the cooling unit 62 is mounted in a sufficiently mounted state. The microphone corresponds to the sound detection unit.

Further, although the laser ignition device 300 of the present embodiment does not have a temperature detection function like the laser ignition device 200 of the second embodiment, the cooling unit 62 may be further provided with a temperature detection function. .. As a result, in addition to the configuration for cooling the laser spark plug 12, the laser light source 3 is controlled based on not only the mounting state of the cooling unit 62 on the laser spark plug 12 but also the temperature of the laser spark plug 12 and the detection state of the laser beam. It can be carried out.

(Modified example of the third embodiment)
In the third embodiment, the cooling unit is provided with a laser detection function for detecting the generation of laser light by the Q switch of the laser ignition plug, but the laser ignition plug 12 can be used by a method other than the external unit. If it is possible to sufficiently dissipate heat and cool it, a configuration having a laser detection function may be provided without a heat dissipation / cooling system.

FIG. 11 is a diagram showing a state in which the external unit is attached to the laser spark plug of the laser ignition device of the modified example of the third embodiment. FIG. 11 corresponds to FIG. 8A and shows a state (non-attached state) before the external unit 63 is attached to the laser ignition plug 12. In this modification, instead of the cooling unit 62 of the third embodiment, an external unit 63 provided with a continuity detection function and a laser detection function is provided. The laser ignition device 300'of this modification is the same as the laser ignition device 300 of the third embodiment except that it does not have a cooling function.

As described above, even when the laser ignition device 300'of the present modification is configured, the same effect as that of the laser ignition device 300 of the third embodiment is obtained.

Although the specific embodiments of the present invention have been described in detail above, the present invention is not limited to the above-described embodiments as they are, and various modifications and changes are made at the implementation stage without departing from the gist thereof. However, it can be materialized.

For example, the present invention is not limited to the case where a cooling unit or the like is attached to the laser ignition device as in the present embodiment. That is, it can also be applied to a case where an external unit having a function other than the cooling function, the temperature detection function, and the laser detection function is mounted on a member to be mounted other than the laser ignition device. Further, in the present embodiment, the laser ignition device is provided at the bottom of a hole such as a plug hole, but the environment in which the mounted member is provided is not limited.

1, 12 Laser spark plug 1A Upper member 1B Lower member 1D Groove 1E Straight shape part 2 Plug hole 3 Laser light source 4 Optical fiber 5 Combustion chamber 6, 61, 62 Cooling unit 6A Heat sink 6B1, 6B2 Heat pipe 6C Mounting part 6C1, 6C2 , 6C4 Heat receiving member 6C3 Connection part 6C5 Protrusion part 6C6 Linear shape part 6D1 Sheet-shaped member 6E1, 6E2 Electrode plate 7 Temperature sensor 8 Photodioden 9 Window part 63 External unit 100, 200, 300, 300'Laser spark plug 110, 210 , 310 Ignition control unit 111 Continuity detection unit 112, 212, 312 Light source control unit 113 Notification unit 214 Temperature detection unit 315 Light detection unit

Japanese Patent No. 5813224

Claims (9)

An external unit that is inserted into a hole for accommodating a mounted member having a portion at least partially composed of a conductive member and is mounted in contact with the mounted member.
The main body made of conductive members and
A plurality of sheet-like members provided on the inner wall surface of the main body,
A plurality of contact portions provided on the inner wall surface of each of the plurality of sheet-shaped members, and
A continuity detection unit that detects a state in which the plurality of contact portions are conducting with each other via the portion, and a continuity detection unit.
With
The plurality of sheet-like members are composed of insulating members.
The plurality of contact portions are a plurality of conductive members, and the plurality of contact portions are
The plurality of contact portions are in an insulated state when the external unit is not mounted on the mounted member, and the contact portions of the portion are in an insulated state when the external unit is completely mounted on the mounted member. Contact with the conductive member,
External unit. The mounted member is a laser spark plug.
The external unit according to claim 1, further comprising a light source control unit that controls a light source that emits laser light to the laser ignition plug based on a detection result by the continuity detection unit. The external unit according to claim 2 , further comprising a cooling unit that dissipates heat from the laser spark plug to cool the laser spark plug. Further provided with a temperature detection unit for detecting the temperature of the laser spark plug,
The external unit according to claim 2 or 3, wherein the light source control unit controls the light source based on the detection result of the temperature detection unit. A laser detection unit that detects the generation of laser light by the laser ignition plug is further provided.
The external unit according to claim 2 or 3, wherein the light source control unit controls the light source based on the detection result of the laser detection unit. The external unit according to claim 5, wherein the laser detection unit is a photodetection unit that detects a part of pulsed light excited by a Q switch by a light receiving element. The external unit according to claim 5, wherein the laser detection unit is a sound detection unit that detects a sound generated when a pulsed light is excited by a Q switch or when an air breakdown occurs. In a laser ignition device including a laser ignition plug and an external unit inserted into a hole accommodating the laser ignition plug and attached in contact with the laser ignition plug.
The laser spark plug
It has a first portion that is at least partially composed of a conductive member and has a first portion.
The external unit is
The main body made of conductive members and
A plurality of sheet-like members provided on the inner wall surface of the main body,
A plurality of contact portions provided on the inner wall surface of each of the plurality of sheet-shaped members, and
A continuity detection unit that detects a state in which the plurality of contact portions are conducting with each other via the first portion, and a continuity detection unit.
With
The plurality of sheet-like members are composed of insulating members.
The plurality of contact portions are a plurality of conductive members, and the plurality of contact portions are
The plurality of contact portions are in an insulated state when the external unit is not attached to the laser ignition plug, and the first contact portion is when the external unit is completely attached to the laser ignition plug. Contacting the conductive member of the site,
Laser igniter. The laser spark plug
The laser ignition device according to claim 8, further comprising a second portion having an insulating layer on the surface and made of a member having a higher thermal conductivity than the first portion.

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