WO2016031717A1

WO2016031717A1 - Engine work machine

Info

Publication number: WO2016031717A1
Application number: PCT/JP2015/073535
Authority: WO
Inventors: 直人一橋
Original assignee: 日立工機株式会社
Priority date: 2014-08-29
Filing date: 2015-08-21
Publication date: 2016-03-03

Abstract

The purpose of the present invention is to reduce the temperature of exhaust gas using a simple structure, and to enable a reduction in the size of a muffler cover. The flow direction of exhaust gas discharged rightward from an exhaust-gas outlet hole (43) is changed so as to be rearward by an exhaust-gas restriction member (50), and the exhaust gas passes through an outflow port (44B) and is discharged at the rear of a muffler cover (44). A guide plate (54) is provided to the rear of the exhaust-gas restriction member (50). The guide plate (54) extends so as to protrude further rearward than the rear end of a muffler (40), and serves as a guide for the exhaust gas flowing rearward. The guide plate (54) is bent to the left side in fig. 2, and is set such that an extended line of the guide plate (54) is further outward than a cover inner side surface (44C). As a result of the guide plate (54), the exhaust gas discharged at the rear of the muffler cover (44) flows away from a cover outer side surface (44A).

Description

Engine working machine

The present invention relates to a structure of an engine working machine in which an engine is used as a power source, such as a brush cutter.

Various engine working machines are known in which a small engine or the like is used as a power source, such as a brush cutter, a blower, a chainsaw, or a power cutter.

FIG. 5 is a perspective view showing an example of a configuration of a brush cutter among such engine working machines. In the brush cutter 300, a rotating cutting blade 302 is provided on the front end (one end) side of the operation rod 301 elongated in the front-rear direction. The cutting blade 302 is driven by an engine (not shown) in the power unit 303 provided on the rear end (other end) side of the operation rod 301. For this reason, a transmission shaft (not shown) for transmitting the rotational motion of the engine to the front end side is provided in the operating rod 301. Near the center of the operation rod 301 in the front-rear direction, a handle 304 is provided for an operator to hold during operation.

The power unit 303 incorporates a small two-cycle air-cooled engine. The cylinder of this engine is covered with a cylinder cover, and cooling air generated by a cooling fan fixed to the crankshaft flows through the inside of the cylinder cover, thereby cooling the cylinder that becomes hot during operation. Further, a muffler that allows the exhaust gas to pass through is connected to the cylinder, and this muffler is also covered with the muffler cover in the same manner as the cylinder cover because it becomes high temperature. Since the brush cutter 300 is carried and used by an operator, the cylinder cover and the muffler cover are formed of a lightweight resin material.

By providing the cylinder cover and the muffler cover, it is possible to prevent the operator from accidentally touching the cylinder or the muffler that has become hot. However, the surface temperature of the cylinder cover and muffler cover also rises, although it is lower than the cylinder and muffler. It is clear that the surface temperature can be lowered if the gap between the cylinder cover and the muffler cover is sufficiently large and the gap between the cylinder cover and the muffler cover is widened. It becomes large and becomes unsuitable for carrying. For this reason, for example, in the structure described in Patent Document 1, the cooling air generated by the cooling fan is efficiently flowed in the cylinder cover and the muffler cover, and the surface of the cylinder cover and the muffler cover is not enlarged. The temperature is lowered.

On the other hand, the exhaust gas discharged from the muffler during operation also becomes high temperature. Exhaust gas is usually exhausted from the power section 303 toward the rear (the side opposite to the side where the operation rod 301 in FIG. 5 is provided) so as not to hinder the work. A structure for guiding the cooling air is provided in the cylinder cover, and the temperature of the exhaust gas is lowered by mixing the cooling air that has cooled the cylinder and the muffler and the exhaust gas.

JP 2014-47740 A

When the exhaust gas is mixed with the cooling air in this way, it is necessary to provide a complicated structure inside the muffler cover and the cylinder cover, and the exhaust gas flows through the muffler cover via such a structure. At that time, in order to prevent exhaust gas from contacting the muffler cover as much as possible, the muffler cover and the cylinder cover eventually increased in size.

For this reason, it has been difficult to reduce the temperature of the exhaust gas with a simple structure and to reduce the size of the muffler cover.

The present invention has been made in view of such problems, and an object thereof is to provide an invention that solves the above problems.

In order to solve the above problems, the present invention has the following configurations. In the engine working machine of the present invention, a muffler through which exhaust gas discharged from the engine flows is connected to one side viewed from the cylinder axis of the engine, and the muffler is covered from the one side by a muffler cover, An engine working machine having a configuration in which exhaust gas is discharged backward from an outlet provided behind the muffler cover, wherein the exhaust gas outlet hole through which the exhaust gas is discharged from the muffler is provided. An exhaust gas restricting member that is mounted on the side surface of the one side of the muffler so as to cover the exhaust gas outlet hole, and that directs the flow of the exhaust gas to the rear, and the rear of the muffler toward the rear from the exhaust gas restricting member A guide plate that protrudes rearward from the end and is curved or bent toward the other side opposite to the one side. That. In the engine work machine according to the present invention, the portion of the muffler cover that constitutes the end portion on the other side of the outlet is located on the other side of the extension line on the rear end side of the guide plate. It is characterized by. In the engine work machine of the present invention, the portion of the muffler cover that constitutes an end portion on the one side of the outlet is more than the portion of the muffler cover that constitutes an end portion on the other side of the outlet. It protrudes backward. The engine working machine of the present invention is characterized in that the maximum width in the vertical direction of the exhaust gas outlet hole is made larger than the maximum width in the horizontal direction of the exhaust gas outlet hole. In the engine working machine of the present invention, the exhaust gas regulating member includes an opposing wall surface that faces the exhaust gas outlet hole and directs the flow of the exhaust gas backward, and the rear end portion of the opposing wall surface has the An inclined portion having a shape inclined toward the other side is provided. The engine working machine of the present invention is characterized in that a fixing member for fixing the exhaust gas regulating member to a side surface of the muffler is provided behind the inclined portion. The engine work machine of the present invention is characterized in that an angle toward the other side of the guide plate is in a range of 15 ° to 45 ° with respect to the front-rear direction. The engine work machine of the present invention is characterized in that an angle toward the other side of the guide plate is in a range of 20 ° to 40 ° with respect to the front-rear direction. In the engine working machine of the present invention, a power unit including the engine, the muffler, and the muffler cover is mounted on a rear end of an operating rod, and a cutting blade driven by the engine is provided on the front end of the operating rod. It is a brush cutter.

Since the present invention is configured as described above, the exhaust gas temperature can be lowered with a simple structure, and the muffler cover can be downsized.

It is sectional drawing along the intake / exhaust direction of the motive power part in the brush cutter which becomes embodiment of this invention. It is sectional drawing of the horizontal direction of the area | region containing the muffler of the motive power part in the brush cutter used as embodiment of this invention. It is the partial perspective view seen from the side of the power unit used in the brush cutter which is an embodiment of the invention. It is an assembly perspective view of the power unit used in the brush cutter according to the embodiment of the present invention. It is a perspective view which shows the form of an example of the conventional brush cutter.

A configuration of an engine working machine (brusher) according to an embodiment of the present invention will be described. The overall configuration of the brush cutter is the same as that of the brush cutter 300 shown in FIG. Here, the structure of the power unit 10 used, particularly the structure around the muffler, is characteristic. The power unit 10 is configured such that an operating rod is fixed in front of the power unit 10 and exhaust gas or cooling air is flowed to the rear side.

FIG. 1 is a cross-sectional view of the power unit 10 in this brush cutter along the intake / exhaust direction (the left-right direction for the operator during use). The cylinder 11 of the engine used here is provided on the upper side, in which the piston 12 reciprocates in the vertical direction. With respect to the cylinder axis C of this engine, intake is performed on the left side, exhaust is performed on the right side, and the reciprocating motion of the piston 12 is performed in a crankcase 14 provided on the lower side of the cylinder 11 by a crank mechanism 13 including a connecting rod or the like. Is converted into a rotational motion of the crankshaft (drive shaft) 15. In FIG. 1, a cross section perpendicular to the crankshaft 15 is shown. The crankshaft 15 is provided on an extension line of the operation rod 301 in FIG. 5, and is connected to a transmission shaft in the operation rod 301 via a centrifugal clutch (not shown) provided in front. A cooling fan 16 is fixed behind the centrifugal clutch in the crankshaft 15, and cooling air is generated by the cooling fan 16. The cylinder 11 is covered from the upper side with a resin cylinder cover 17 in a non-contact state, and the cooling air flows through the cylinder 11 to cool the cylinder 11.

A fuel tank 30 in which fuel is stored is provided below the crankcase 14. This fuel is supplied to a carburetor 31 connected to the left side via an intake port 18 and an intake pipe 19 in the cylinder 11. An air cleaner 32 is also connected to the left side of the carburetor 31, and a mixture of air and fuel sucked through the air cleaner 32 is generated by the carburetor 31 and introduced into the crankcase 14 and the cylinder 11. The engine is operated by the air-fuel mixture being compressed by the piston 12 in the cylinder 11 and ignited by the spark plug 20 mounted on the upper portion of the cylinder 11. A current is passed through the spark plug 20 through a plug cap 21 covering the top of the spark plug 20.

Exhaust gas from the cylinder 11 flows through the exhaust port 22 to a muffler 40 mounted on the right side (one side) of the cylinder 11. Inside the muffler 40, a catalyst material 42 is installed fixed to the partition plate 41. The exhaust gas introduced from the cylinder 11 passes through the catalyst material 42 to remove harmful components and unburned fuel components, and is then discharged from the exhaust gas outlet hole 43 to the outside of the muffler 40. In addition to the heat transfer from the cylinder 11 to the muffler 40, an exothermic reaction occurs in the catalyst material 42, so that the muffler 40 during operation becomes high temperature. Therefore, the muffler 40 is covered with a resin muffler cover 44 from the right side. In FIG. 1, the exhaust gas flow EX is indicated by a one-dot chain line arrow, and here, the exhaust gas flow EX in the vertical direction up to the exhaust gas outlet hole 43 is mainly shown. The exhaust gas outlet hole 43 is provided on the right side surface of the muffler 40.

On the other hand, FIG. 2 is a horizontal sectional view of the structure including the muffler 40. In FIG. 2, the flow EX of the exhaust gas in the horizontal direction mainly from the exhaust gas outlet hole 43 is shown. A two-dot chain line in the figure indicates the center axis O of the crankshaft 15. In the power unit 10, a metal exhaust gas regulating member 50 is mounted on the side surface of the muffler 40 so as to cover the exhaust gas outlet hole 43 in order to realize the flow of the exhaust gas EX shown in FIG. Yes. Here, in order to make the muffler cover 44 and the muffler 40 close to each other and to efficiently flow the cooling air inside, the side surface of the muffler 40 in which the exhaust gas outlet hole 43 is provided is provided on the side of the muffler cover 44 facing the muffler cover 44. It is substantially parallel to the side surface (cover outer side surface 44A). The exhaust gas regulating member 50 is located between the side surface of the muffler 40 and the cover outer side surface 44A. In addition, an outlet 44 </ b> B is provided behind the muffler cover 44 for discharging exhaust gas and cooling air to the rear. As shown in FIG. 2, the outlet 44B is defined by an inner cover inner side surface 44C and a protrusion 44D that is a rearward protruding portion of the outer cover outer side surface 44A in the horizontal plane. That is, the cover inner side surface 44C constitutes an end portion on the left side (the other side) of the outflow port 44B, and the projecting portion 44D constitutes an end portion on the right side (one side) of the outflow port 44B.

FIG. 3 is a partial perspective view of the power unit 10 viewed from the side where the muffler 40 is located. FIG. 4 is an assembly perspective view of the exhaust gas regulating member 50, the muffler cover 44, and the like in the power unit 10. FIG. 4 is a perspective view seen obliquely from the rear, and the rear structure of the engine, the muffler cover 44, etc. is shown in the perspective view. As shown in FIG. 4, the cylinder cover 17 and the muffler cover 44 are actually integrated. In addition, a starting device 23 for forcibly rotating the crankshaft 15 to start the engine is provided behind the crankcase 14, and an operator pulls a starting handle 24 attached to the starting device 23, thereby The engine can be started. The fuel tank 30 is provided with a tank cap 30A that can be easily attached and detached when fuel is supplied.

As shown in FIG. 4, the exhaust gas outlet hole 43 in the muffler 40 has a vertically long shape, that is, its opening width in the vertical direction is wider than its opening width in the front-rear direction. For this reason, the exhaust gas is discharged from the muffler 40 in a wide range extending in the vertical direction of the exhaust gas outlet hole 43. Further, as shown in FIG. 4, the exhaust gas regulating member 50 includes a metal mesh portion 51 serving as a spark arrester and a gasket 52 in which an opening corresponding to the exhaust gas outlet hole 43 is sandwiched. Attached to the side surface by three screws (fixing members) 53. The exhaust gas discharged in the right direction from the exhaust gas outlet hole 43 is changed in the flow direction to the rear by the exhaust gas restricting member 50 and is discharged to the rear of the muffler cover 44 through the outlet 44B.

As shown in FIG. 2, the outer peripheral portion of the exhaust gas restricting member 50 has a planar shape that comes into close contact with the gasket 52 when attached. However, the portion corresponding to the exhaust gas outlet hole 43 has a convex shape in a direction away from the exhaust gas outlet hole 43, and the convex wall portion 50A faces the parallel wall surface 50A substantially parallel to the side surface of the muffler 40. Is formed. Since the front, upper, and lower sides of the opposing wall surface 50A and the gasket 52 are connected to the planar portions that are in close contact with the gasket 52, the front, upper, and lower sides of the opposing wall surface 50A and the gasket 52 are closed. Is done. On the other hand, since an opening is provided behind the opposed wall surface 50A, the exhaust gas hits the opposed wall surface 50A and does not flow forward, upward, or downward, but flows backward. Since the flow of the exhaust gas to the side (right direction in FIG. 2) is restricted by the opposing wall surface 50A, the exhaust gas does not directly hit the cover outer side surface 44A, and the muffler cover is used to reduce the influence of the exhaust gas. There is no need to increase the size of 44. At this time, the exhaust gas outlet hole 43 has a vertically long shape and the opposing wall surface 50A is used, so that the exhaust gas can flow backward in a wide range in the vertical direction. Since the exhaust gas regulating member 50 has a simple structure, it can be easily manufactured by sheet metal processing. Further, although the thickness corresponding to the formation of the opposing wall surface 50A is necessary, the entire exhaust gas regulating member 50 can be formed sufficiently thin. Further, although the high temperature exhaust gas directly hits the exhaust gas regulating member 50, the exhaust gas regulating member can be formed of a metal having high heat resistance.

A guide plate 54 is provided behind the exhaust gas regulating member 50. The guide plate 54 extends so as to protrude rearward from the rear end of the muffler 40 and serves as a guide for exhaust gas flowing rearward. However, the guide plate 54 bends to the left side (the other side) in FIG. 2 while being separated from the muffler 40, and its extension line is outside the cover inner side surface 44C (the right side in FIG. 2: one side). Is set. In other words, the guide plate 54 is bent at an angle toward the other side opposite to one side on the rear side. The guide plate 54 may have a curved shape whose angle gradually changes toward the other side. Further, the guide plate 54 may be manufactured separately from the exhaust gas regulating member 50 or may be fixed to the exhaust gas regulating member 50 or may be manufactured integrally with the exhaust gas regulating member 50. In any case, the guide plate 54 is a smaller and lighter component than the muffler cover 44, similarly to the exhaust gas regulating member 50.

Here, the bending angle of the guide plate 54 is sufficient to spread the exhaust gas flowing from the exhaust gas regulating member 50 to the left side (the other side), and the angle (angle with respect to the front-rear direction) is about 15 °. It is desirable that it is in the range of up to 45 °, and particularly in the range of about 20 ° to 40 ° is suitable for reducing the size of the engine working machine. When the angle is smaller than this range, the effect of diffusing the exhaust gas is not sufficient, and when the angle is larger than this range, the exhaust gas does not follow the angle set by peeling off from the surface of the guide plate 54 depending on the flow velocity. There is a possibility that the effect as a guide is less likely to occur. That is, the rear end of the guide plate 54 faces the rear side, but the rear end side is bent or curved in a range inclined moderately from the front-rear direction.

By the guide plate 54, the exhaust gas discharged to the rear of the muffler cover 44 flows away from the cover outer side surface 44A. For this reason, even when the muffler cover 44 is downsized so that the cover outer side surface 44A is close to the muffler 40 or the exhaust gas regulating member 50, the exhaust gas is prevented from hitting the cover outer side surface 44A.

Further, the exhaust gas flowing backward along the opposing wall surface 50A by the guide plate 54 spreads to the left side (the other side). For this reason, the exhaust gas is diffused and mixed with air to lower its temperature. That is, it is possible to reduce the temperature of the exhaust gas by using the exhaust gas restricting member having a simple structure, and to suppress the temperature rise of the muffler cover 44 due to the exhaust gas. Further, since the temperature of the exhaust gas when passing through the outlet 44B is lowered, even if the exhaust gas hits the muffler cover 44 around the outlet 44B, the temperature rise is small, but the cover inner side surface 44C is rearward. If the length of the guide plate 54 is shortened and the extension line of the guide plate 54 is set to be outside the cover inner side surface 44C, it is possible to prevent the exhaust gas from hitting the cover inner side surface 44C. In this case, even when the muffler cover 44 is downsized, the temperature of the muffler cover 44 is further suppressed from increasing due to the exhaust gas.

Since the guide plate 54 is used, it is possible to prevent the exhaust gas from hitting the cover outer side surface 44A regardless of the rear protrusion length of the protrusion 44D (cover outer side surface 44A). This can be appropriately set within a range in which the entire drive unit 10 is not enlarged. In a brush cutter, the grass or trees that are cut off may block the exhaust gas path and exhaust the exhaust gas in an unintended direction, but this problem can be reduced by increasing the protruding length. Can do.

Moreover, the upper part and the lower part of the opposing wall surface 50A are connected to the flat part in close contact with the gasket 52 in the exhaust gas regulating member 50 as described above. As shown in FIG. 3, the distance in the vertical direction between the upper side (opposite wall upper part 50A1) and the lower side (opposite wall lower part 50A2) of the opposing wall surface 50A connected to the flat portion of the gasket 52 in this way is from the front. The shape is widened toward the rear. For this reason, the exhaust gas flowing between the gasket 52 and the opposing wall surface 50A spreads in the vertical direction toward the rear. That is, the exhaust gas is diffused by the exhaust gas regulating member 50 not only in the left-right direction but also in the up-down direction. Also in this case, it is preferable that the muffler cover 44 does not exist on the extension lines (broken lines X1 and X2 in FIG. 3) of the opposing wall surface upper part 50A1 and the opposing wall surface lower part 50A2.

Further, as shown in FIG. 2, the rear end portion of the opposing wall surface 50 </ b> A is an inclined portion 50 </ b> B that does not contact the gasket 52 but is inclined toward the gasket 52 side so that the interval between the gasket 52 is narrowed. Yes. For this reason, since the horizontal width of the exhaust gas flow path in the vicinity of the rear end of the opposing wall surface 50A is narrowed, the flow velocity is increased, and a negative pressure is generated in this portion, which is indicated by a dotted arrow in FIG. The air flow A mixed into the exhaust gas. That is, air can be mixed into the exhaust gas at this portion, and the temperature of the exhaust gas can also be lowered by this.

In addition, as shown in FIG. 4, the exhaust gas regulating member 50 is attached to the muffler 40 using a plurality of screws 53. In order to increase the adhesion between the exhaust gas regulating member 50 and the muffler 40 (gasket 52) and suppress the flow of exhaust gas other than the rear, it is preferable that the number of screws 53 used for this purpose is large. In three and four, three screws 53 are used. Here, as shown in FIGS. 3 and 4, on the downstream side of the exhaust gas flow (left side in FIG. 3), the exhaust gas flow is obstructed, so the number of screws 53 is reduced as much as possible. Is preferably used. In this case, since the downstream screw 53 is always exposed to high-temperature exhaust gas, the deterioration tends to occur, and the screw 53 may be damaged or stuck after long-term use. On the other hand, as shown in FIG. 3, the screw 53 can be cooled by the airflow A by providing the screw 53 on the downstream side (rear side) of the inclined portion 53B. That is, by providing the screw 53 used for fixing the exhaust gas fixing member 50 on the downstream side (rear side) on the downstream side (rear side) of the inclined portion 53B, deterioration of the screw 53 can be suppressed. In addition, since the two screws 53 on the upstream side (front side) in FIG. 3 are not exposed to the exhaust gas, such deterioration hardly occurs. The same applies to the case where the exhaust gas regulating member is fixed using a fixing member other than a screw.

In the above description, the flow of cooling air for cooling the cylinder and the muffler is not mentioned. However, when this cooling air is also discharged from the outlet, the diffused exhaust gas is also mixed with this cooling air, so it is clear that this also further reduces the temperature of the exhaust gas.

In addition, although the above example is a brush cutter provided with the above-mentioned power unit, even if it is a working machine other than the brush cutter, it is an engine working machine that similarly uses an engine, a muffler, and a muffler cover. It is clear that the same effect can be obtained.

DESCRIPTION OF SYMBOLS 10,303 ... Power part, 11 ... Cylinder, 12 ... Piston, 13 ... Crank mechanism, 14 ... Crankcase, 15 ... Crankshaft (drive shaft), 16 ... Cooling fan, 17 ... Cylinder cover, 18 ... Intake port, 19 DESCRIPTION OF SYMBOLS ... Intake pipe, 20 ... Spark plug, 21 ... Plug cap, 22 ... Exhaust port, 23 ... Starter, 24 ... Start handle, 30 ... Fuel tank, 30A ... Tank cap, 31 ... Vaporizer, 32 ... Air cleaner, 40 ... Muffler, 41 ... Partition plate, 42 ... Catalyst material, 43 ... Exhaust gas outlet hole, 44 ... Muffler cover, 44A ... Cover outer side face, 44B ... Outlet outlet, 44C ... Cover inner side face, 44D ... Protrusion, 50 ... Exhaust Gas regulating member, 50A ... opposing wall surface, 50A1 ... opposing wall upper surface, 50A2 ... opposing wall lower surface, 50B ... inclined portion, 51 ... mesh portion, 52 ... gasket 53 ... Screw (fixing member), 54 ... Guide plate, 300 ... Brush cutter (engine working machine), 301 ... Operating rod, 302 ... Cutting blade, 304 ... Handle, A ... Air flow, C ... Cylinder axis, EX ... Exhaust Gas flow, O ... center axis of crankshaft, X1 ... extension line at the upper part of the opposing wall surface, X2 ... extension line at the lower part of the opposing wall surface

Claims

A muffler through which exhaust gas discharged from the engine flows is connected to one side viewed from the cylinder axis of the engine, the muffler is covered from the one side by a muffler cover, and the exhaust gas is behind the muffler cover An engine working machine having a configuration in which the exhaust gas is exhausted rearward from an outlet provided in the exhaust pipe, and the exhaust gas outlet hole through which the exhaust gas is exhausted from the muffler is provided. Is mounted so as to cover the exhaust gas outlet hole, and the exhaust gas restricting member for directing the flow of the exhaust gas to the rear, and protrudes rearward from the rear end of the muffler toward the rear from the exhaust gas restricting member, An engine work machine comprising: a guide plate curved or bent toward the other side opposite to the one side.
The portion of the muffler cover that constitutes an end portion on the other side of the outflow port is present on the other side of the extension line on the rear end side of the guide plate. The engine working machine described.
The portion of the muffler cover constituting the end portion on the one side of the outlet port protrudes rearward from the portion of the muffler cover constituting the end portion on the other side of the outlet port. The engine working machine according to claim 2.
The maximum width in the up-down direction of the exhaust gas outlet hole is made larger than the maximum width in the horizontal direction of the exhaust gas outlet hole, according to any one of claims 1 to 3. Engine work machine.
The exhaust gas regulating member has an opposing wall surface facing the exhaust gas outlet hole and directing the flow of the exhaust gas backward, and a rear end portion of the opposing wall surface is inclined toward the other side. The engine working machine according to any one of claims 1 to 4, wherein an inclined portion having a shape is provided.
The engine working machine according to claim 5, wherein a fixing member for fixing the exhaust gas regulating member to a side surface of the muffler is provided behind the inclined portion.
The engine according to any one of claims 1 to 6, wherein an angle toward the other side of the guide plate is in a range of 15 ° to 45 ° with respect to the front-rear direction. Work machine.
The engine working machine according to claim 7, wherein an angle toward the other side of the guide plate is in a range of 20 ° to 40 ° with respect to the front-rear direction.
A power cutter including the engine, the muffler, and the muffler cover is mounted on a rear end of an operating rod, and is a brush cutter including a cutting blade driven by the engine at the front end of the operating rod. The engine work machine according to any one of claims 1 to 8.