JP2005140478A - Ignition device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To protect an ignition element and an IC from a gas released from an explosive while ensuring a function as an ignition device.
In a bus connection ignition device 2a ..., a communication / ignition unit 50 connected to a bus line via a pin is accommodated in an inner cap 41 together with a first explosive 54a that does not release corrosive gas. . Furthermore, between this inner cap 41 and the outer cap 42 that accommodates it, a second explosive 54b that is a different type of explosive from the first explosive 54a and is used as a squib explosive for an existing inflator. Fill.
[Selection] Figure 4

Description

  The present invention relates to an ignition device (squib) used in a system using explosives such as an air bag device and a pretensioner device for automobiles.

Occupant protection devices such as air bag devices and pretensioner devices mounted on automobiles, gas generating agents stored in inflators are ignited by a squib (ignition device), and high-pressure gas generated by the combustion is introduced into air bags, etc. It operates by being done.
The squib has a structure in which an ignition element is attached to a header to which a pin serving as a connection terminal is fixed, and an explosive as an igniter is pressed into the cap so as to contact the ignition element. And the pin fixed to the header is electrically connected with the control unit used as a master.

In recent years, many occupant protection devices such as an airbag device that is deployed from a steering wheel, a side portion of a seat, and a side portion of a roof have been mounted on a vehicle. An invention relating to the formation of a bus between occupant protection devices has been proposed (for example, Patent Document 1).
In addition, an invention related to a squib in which an IC (Integrated Circuit) for communication and ignition is mounted is proposed in accordance with the bus formation (for example, Patent Document 2).
Japanese Patent Laid-Open No. 10-154992 Japanese Patent No. 3294582

By the way, a squib having an IC mounted therein has an advantage that the squib has the same external shape as that of a conventional product and the ignition element is integrated with the IC, so that it can be easily mounted on an existing inflator. .
However, in the structure in which the ignition element is integrated with the IC, the explosive and the IC coexist in the cap, so that the ignition element and the IC are protected from the gas released from the explosive. preferable.

  The present invention has been made in view of the above circumstances, and an object thereof is to protect the ignition element and the IC from the gas released from the explosive while ensuring the function as the ignition device.

In order to solve the above-described problems, the present invention connects a plurality of control devices (for example, the control unit 1 in the embodiments described later) via a common bus line (for example, the bus line 3 in the embodiments described later). For bus connection that can be selectively operated by electric energy (for example, electric power in an embodiment described later) and an electric signal (for example, a control signal and an ignition execution signal in an embodiment described later) supplied from the control device. An ignition device (for example, an ignition device 2a, 2b, 2c,... In an example described later),
A communication / ignition circuit electrically connected to the bus line (for example, a control circuit 21 mounted on an IC substrate 52 in an embodiment to be described later), and an ignition element (for example, connected to the communication / ignition circuit) The communication / ignition unit (for example, the communication / ignition unit 50 in the example described later) including the ignition element 30 in the example described later is a first explosive (for example, the first explosive 54a in the example described later). ) And an inner cap (for example, an inner cap 41 in an embodiment described later),
A second explosive different from the first explosive (for example, a second explosive in a later-described embodiment) is provided between the inner cap and an outer cap (for example, an outer cap 42 in the later-described embodiment). The explosive 54b) is filled.

Also, the present invention is a bus connection ignition device which is connected to a plurality of control devices via a common bus line and can be selectively operated by electrical energy and electrical signals supplied from the control device. ,
A communication / ignition unit including a communication / ignition circuit electrically connected to the bus line and an ignition element connected to the communication / ignition circuit includes a first explosive and a first chamber (for example, described later) In the inner cap 41 in the embodiment)
The first chamber is a second chamber (for example, an inner bottom surface 42A of an outer cap 42 in an embodiment described later) and an inner cap whose gas flow is blocked by a partition wall (for example, an inner cap 41 in an embodiment described later). 41 may be filled with a second explosive different from the first explosive.

  Furthermore, in the present invention, it is preferable that an explosive that does not release corrosive gas (for example, tricinate in the examples described later) is used as the first explosive.

  According to the above configuration, even if the gas is released from the second explosive, since the gas flow is blocked by the inner cap or the partition wall, the ignition element and the communication / ignition circuit are not touched.

According to the first and second aspects of the invention, even if gas is released from the second explosive, the gas flow is blocked by the inner cap or the partition wall, and does not touch the ignition element or the communication / ignition circuit. As the first explosive, an explosive that eliminates influence on the ignition element and the communication / ignition circuit as much as possible can be used, and as the second explosive, an explosive suitable for ensuring the function of the ignition device can be used.
According to the third aspect of the invention, it is possible to more effectively suppress the influence of the gas released from the first explosive on the ignition element and the communication / ignition circuit.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments that are the best mode of the present invention will be described below with reference to FIGS.
The ignition device according to this embodiment is suitable for use in an occupant protection device such as an airbag device or a pretensioner device mounted on a vehicle such as an automobile. Hereinafter, as an example, a case where an occupant protection device including an ignition device is mounted on an automobile will be described.

  In FIG. 1, a control unit 1 is a control unit that forms the center of an occupant protection device that protects an occupant from an impact applied to the vehicle, and a plurality of auxiliary restraint devices provided at appropriate positions of the vehicle to protect the occupant The auxiliary restraint igniters 2a, 2b, 2c,... Provided in one-to-one (not shown), for example, using an unbalanced bus line 3 in which one of two pairs of wires is installed. It is connected. The ignition devices 2a, 2b, 2c,... Are devices that operate the auxiliary restraint device using an igniting agent (an explosive that ignites the gas generating agent of the auxiliary restraining device), and includes an igniting agent 54 inside The auxiliary restraint device is ignited by igniting the igniter 54 based on the ignition execution signal (ignition execution command) sent from the control unit 1 by designating the communication addresses of the ignition devices 2a, 2b, 2c,. Operate.

  Further, the control unit 1 is provided with a collision determination unit 11 realized by a CPU (Central Processing Unit). The collision determination unit 11 is provided in the front part of the vehicle and connected via a communication circuit 12. Based on the output signal of the front sensor 4 that detects the acceleration due to the deformation of the front part of the vehicle and the output signal of the G sensor 13 that is provided in the control unit 1 and detects the acceleration of the vehicle, the vehicle It is determined whether or not an impact that requires the operation of the occupant protection device has been applied to the vehicle due to the collision.

  On the other hand, the control unit 1 is supplied with electric power (electric energy) to the ignition devices 2a, 2b, 2c,... Via the bus line 3, and designated with a communication address, the ignition devices 2a, 2b, 2c,. When the communication circuit 14 for performing communication of the control signal (electric signal) is provided, and the collision determination unit 11 determines that an unnecessary impact is applied to the vehicle due to the vehicle colliding with another object, An ignition execution signal (ignition execution command) for operating the auxiliary restraint device (not shown) is sent to the ignition devices 2a, 2b, 2c,... Via the bus line 3 by the communication circuit 14.

The control unit 1 is connected to an in-vehicle battery 7 for storing electric power used in the vehicle via a fuse 5 and an ignition switch (IG / SW) 6 for preventing overcurrent, and reverse current flow The electric power of the in-vehicle battery 7 input through the protection diode 15 for preventing the collision is supplied to the + 5V power source 16 that generates the power source of the CPU or the like that constitutes the collision determination unit 11, and the ignition devices 2a, 2b, 2c, Is also supplied to the communication circuit 14 for supplying power to. Further, the control unit 1 stores a backup capacitor 17 that stores power and backs up the power source so as to operate for a certain period of time even when power supply from the in-vehicle battery 7 is stopped, and for charging the backup capacitor 17. Protection diodes 18a and 18b, a booster circuit 19 and the like are also provided.
Since the ignition devices 2a, 2b, 2c,... Connected to the common bus line 3 are configured in the same manner, the ignition device 2a will be described below as an example.

As shown in FIG. 2, the ignition device 2 a is provided with a control circuit 21 that executes communication control through the bus line 3 and ignition control based on an instruction from the control unit 1. A control signal (command) is input to the control circuit 21 via 22, and a response signal (response) to the control signal is output from the control circuit 21 to the bus line 3 via the transmission buffer 23.
The electric power supplied from the bus line 3 is supplied to a + 5V power source 24 that generates a power source for the control circuit 21 and the like, and the ignition device 2a ignites the igniting agent via the protective diode 25 to operate the auxiliary restraint device. It is also supplied to a booster circuit 26 that generates electric power necessary for the operation.

A capacitor 28 is connected to the output of the booster circuit 26 via a protective diode 27. The capacitor 28 is boosted by the booster circuit 26, which is necessary for the ignition device 2a to ignite the igniting agent and operate the auxiliary restraint device. It is configured to be able to store the stored power.
At the output (cathode terminal) of the protection diode 27, a series circuit of a switching element 29, an ignition element 30 for igniting an igniting agent built in the ignition device 2 a, and a switching element 31 is provided in parallel with the capacitor 28. It is connected. Specifically, one terminal of the ignition element 30 is connected to the output of the protection diode 27 via the switching element 29, and the other terminal of the ignition element 30 is grounded via the switching element 31. ing. Both control terminals that control conduction and interruption of the switching element 29 and the switching element 31 are connected to the control circuit 21.

As shown in FIGS. 3 and 4, the ignition device 2 a includes a cap unit 40 having a bottomed cylindrical shape, and a communication / ignition unit 50 accommodated coaxially in the cap unit 40.
In addition, the cap unit 40 and the communication / ignition unit 50 are configured such that an inner cap 41 that is a component of the cap unit 40 and a header 51 that is a component of the communication / ignition unit 50 are integrated by, for example, laser welding. The periphery of the opening of the cap unit 40 is sealed by the resin molding 55.

The cap unit 40 includes a bottomed cylindrical inner cap 41 into which the communication / ignition unit 50 is coaxially inserted, and a bottomed cylindrical outer cap 42 into which the inner cap 41 is coaxially inserted. These metal caps 41 and 42 such as SUS are interconnected by, for example, laser welding.
The inner cap 41 (first chamber), more specifically, the gap between the inner bottom surface (inner wall) 41A of the inner cap 41 and the front end surface (outer wall) 50A of the communication / ignition unit 50 has a second gap. The first explosive 54a is filled, and a second explosive 54b is formed in a gap (second chamber) between the inner bottom surface (inner wall) 42A of the outer cap 42 and the outer bottom surface (outer wall) 41B of the inner cap 41. It is filled.

The communication / ignition unit 50 includes a header 51 having a tubular insulating member 51b inside a header body 51a having conductivity, and an IC substrate for communication / ignition connected to the tip of the header 51 by, for example, welding. 52, and pins 53a and 53b which are connection terminals to the two-wire bus line 3 which is an external signal line are fixed to the header 51.
The IC substrate 52 includes the control circuit 21, the reception buffer 22, the transmission buffer 23, the + 5V power supply 24, the protection diode 25, the booster circuit 26, the protection diode 27, the capacitor 28, the switching element 29, the ignition element 30, and the like. A switching element 31 is mounted.

The first explosive 54 a is in direct contact with the IC substrate 52. Therefore, in order to protect components such as the control circuit 21 and the ignition element 30 mounted on the IC substrate 52 from the gas released from the first explosive 54a, for example, trisinate (lead trinitroresorcate, C Explosives that do not release corrosive gases such as ₆ H (NO ₂ ) ₃ O ₂ Pb) are used.
On the other hand, the second explosive 54b is isolated from the IC substrate 52 through the inner cap 41 so as not to be in contact with it, and the gas released from the second explosive 54b cannot flow to the IC substrate 52 side. It is kept in a state. Therefore, for the second explosive 54b, an existing squib explosive suitable for ignition of a gas generating agent such as ZPP is used.
As described above, the igniting agent 54 that ignites the gas generating agent of the auxiliary restraint device includes the first and second explosives 54a and 54b of different types.

Assembly of the ignition device 2a is performed, for example, according to the following procedure.
First, as shown in FIG. 3, after inserting the second explosive 54b and the inner cap 41 into the outer cap 42 in this order, the outer cap 42 and the inner cap 41 are integrated by welding to form a cap unit 40. Keep it. Separately, the communication / ignition unit 50 is configured by welding the IC substrate 52 to the front end surface 51 </ b> A of the header 51 and integrating them.
Next, the first explosive 54a and the communication / ignition unit 50 are inserted into the cap unit 40 in this order, and the inner cap 41 of the cap unit 40 and the header 51 of the communication / ignition unit 50 are integrated by laser welding. .

At this time, the opening end 41 a of the inner cap 41 extends a predetermined length outward in the axial direction from the opening end 42 a of the outer cap 42.
In addition, the ignition element 30 connected to the switching element 29 and the switching element 31 is disposed at the tip of the IC substrate 52 and in contact with the first explosive 54a. Electric power for ignition and a control signal for the control circuit 21 are supplied via the header 51.

As shown in FIG. 4, the integrated cap unit 40 and communication / ignition unit 50 include the open end portions 42a and 41a of the outer cap 42 and the inner cap 41 of the cap unit 40, and the communication / ignition unit 50. These pins 53a and 53b are sealed with a resin molding 55 so as to straddle the portions near the header 51.
That is, the communication / ignition unit 50 coexists in the inner cap 41 (first chamber) together with the first explosive 54a, which is a closed chamber in which gas flow is blocked by the inner cap (partition wall) 41, that is, A gap (second chamber) between the inner bottom surface 42A of the outer cap 42 and the outer bottom surface 41B of the inner cap 41 is filled with the second explosive 54b.

  In the ignition system including the ignition devices 2a, 2b, 2c,... According to this embodiment, when the control unit 1 supplies power to the bus line 3, the ignition element 30 of the ignition device 2a is ignited 54, that is, the first and first ignition devices. The electric power necessary for igniting the second explosives 54a and 54b in this order to operate the auxiliary restraint device is stored in the capacitor 28. In this state, the control unit 1 sends an ignition execution signal (ignition execution signal) to the ignition device 2a. Command), the control circuit 21 of the ignition device 2a causes the switching element 29 and the switching element 31 to conduct, energizes the electric power stored in the capacitor 28 to the ignition element 30, and the ignition agent built in the ignition device 2a. 54 can be exploded to activate the auxiliary restraint device.

And according to the ignition devices 2a, 2b, 2c,... According to this embodiment, even if a corrosive gas (for example, chlorine) is released from the second explosive 54b, the gas can be circulated. Since it is blocked by the inner cap 41 that also functions as a partition in addition to the casing, corrosive gas does not touch the IC substrate 52.
Therefore, the first explosive 54a can use explosives that eliminate the influence on the IC substrate 52 as much as possible, for example, explosives such as tricinate that does not release corrosive gas, and the second explosive 54b ensures the function of the ignition device. Suitable explosives, that is, explosives such as ZPP that can be easily ignited can be used as the gas generating agent.

In addition, this invention is not limited to the said Example, A various design change is possible in the range which does not deviate from the summary.
For example, in the case of an ignition device used in a system using explosives, its application target is not limited to an occupant protection device such as an airbag device or a pretensioner device mounted on an automobile, and can be applied in various ways. is there.

1 is a block diagram of an ignition system including an ignition device according to an embodiment of the present invention. It is a block diagram of the ignition device by the Example. It is an exploded sectional view of the ignition device by the example. It is a longitudinal cross-sectional view of the ignition device by the Example.

Explanation of symbols

1 Control unit (control device)
2a, 2b, 2c Ignition device 3 Bus line 21 Control circuit (part of communication / ignition circuit)
30 Ignition element 41 Inner cap (partition wall)
42 outer cap 50 communication / ignition unit 52 IC substrate 54a first explosive 54b second explosive

Claims (4)

A plurality of ignition devices for connecting a bus connected to a control device via a common bus line and selectively operable by electrical energy and electrical signals supplied from the control device,
A communication / ignition unit including a communication / ignition circuit electrically connected to the bus line and an ignition element connected to the communication / ignition circuit is housed in the inner cap together with the first explosive,
An ignition device characterized in that a second explosive different from the first explosive is filled between the inner cap and an outer cap that accommodates the inner cap. A plurality of ignition devices for connecting a bus connected to a control device via a common bus line and selectively operable by electrical energy and electrical signals supplied from the control device,
A communication / ignition unit including a communication / ignition circuit electrically connected to the bus line and an ignition element connected to the communication / ignition circuit coexists in the first chamber together with the first explosive,
An ignition device characterized in that a second explosive different from the first explosive is filled in a second chamber in which gas flow is blocked by a partition wall from the first chamber.   The ignition device according to claim 1, wherein an explosive that does not release corrosive gas is used as the first explosive. The ignition device according to claim 3, wherein trisinate is used for the first explosive.

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